Summary Prospectus
August 31, 2015, as revised November 2, 2015

Loomis Sayles Multi-Asset Income Fund

Ticker Symbol: Class A (IIDPX), Class C (CIDPX), Class N (LMINX) and Class Y (YIDPX)

Before you invest, you may want to review the Fund's Prospectus, which contains more information about the Fund and its risks. You can find the Fund's Prospectus and other information about the Fund online at ngam.natixis.com/funddocuments. You can also get this information at no cost by calling 800-225-5478 or by sending an e-mail request to NatixisFunds@ngam.natixis.com. The Fund's Prospectus and Statement of Additional Information, each dated August 31, 2015, as may be revised or supplemented from time to time, are incorporated by reference into this Summary Prospectus.

Investment Goal

The Fund seeks current income with a secondary objective of capital appreciation.

Fund Fees & Expenses

The following table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $100,000 in the Natixis Fund Complex. More information about these and other discounts is available from your financial professional and in the section "How Sales Charges Are Calculated" on page 13 of the Prospectus and on page 119 in the section "Reduced Sales Charges" of the Statement of Additional Information ("SAI").

Shareholder Fees

(fees paid directly from your investment)	Class A		Class C		Class N	Class Y
Maximum sales charge (load) imposed on purchases (as a percentage of offering price)	4.25	%	None		None	None
Maximum deferred sales charge (load) (as a percentage of original purchase price or redemption proceeds, as applicable)	None *		1.00	%	None	None
Redemption fees	None		None		None	None

^* A 1.00% contingent deferred sales charge ("CDSC") may apply to certain purchases of Class A shares of $1,000,000 or more that are redeemed within eighteen months of the date of purchase.

Annual Fund Operating Expenses

(expenses that you pay each year as a percentage of the value of your investment)	Class A		Class C		Class N		Class Y
Management fees	0.55	%	0.55	%	0.55	%	0.55	%
Distribution and/or service (12b-1) fees	0.25	%	1.00	%	0.00	%	0.00	%
Other expenses	0.26	%	0.26	%	0.20	% 1	0.27	%
Total annual fund operating expenses	1.06	%	1.81	%	0.75	%	0.82	%
Fee waiver and/or expense reimbursement 2,3	0.11	%	0.11	%	0.10	%	0.12	%
Total annual fund operating expenses after fee waiver and/or expense reimbursement	0.95	%	1.70	%	0.65	%	0.70	%

¹ Other expenses are estimated for the current fiscal year.

² The Fund's investment adviser has given a binding contractual undertaking to the Fund to limit the amount of the Fund's total annual fund operating expenses to 0.95%, 1.70%, 0.65% and 0.70% of the Fund's average daily net assets for Class A, C, N and Y shares, respectively, exclusive of brokerage expenses, interest expense, taxes, acquired fund fees and expenses, organizational and extraordinary expenses, such as litigation and indemnification expenses. This undertaking is in effect through April 30, 2017 and may be terminated before then only with the consent of the Fund's Board of Trustees. The Fund's investment adviser will be permitted to recover, on a class by class basis, management fees waived and/or expenses reimbursed to the extent that expenses in later periods fall below the applicable expense limitations for Class A, C, N and Y shares. The Fund will not be obligated to repay any such waived/reimbursed fees and expenses more than one year after the end of the fiscal year in which the fees or expenses were waived/reimbursed.

³ NGAM Advisors has given a binding contractual undertaking to the Fund to reimburse any and all transfer agency expenses for Class N shares. This undertaking is in effect through April 30, 2017 and may be terminated before then only with the consent of the Fund's Board of Trustees.

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Fund Summary

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods (except where indicated). The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same, except that the example is based on Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement for the first 20 months and on the Total Annual Fund Operating Expenses for the remaining periods. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

If shares are redeemed:	1 year		3 years		5 years		10 years
Class A	$	518	$	730	$	968	$	1,648
Class C	$	273	$	551	$	963	$	2,112
Class N	$	66	$	223	$	400	$	915
Class Y	$	72	$	241	$	435	$	995

If shares are not redeemed:	1 year		3 years		5 years		10 years
Class C	$	173	$	551	$	963	$	2,112

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes for you if your Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. During its most recently ended fiscal year, the Fund's portfolio turnover rate was 41% of the average value of its portfolio.

Investments, Risks and Performance

Principal Investment Strategies

The Fund intends to pursue its investment goal by utilizing a flexible investment approach that allocates investments across a broad range of income-producing securities, while employing risk management strategies to mitigate downside risk. The Fund may invest in equity securities (including common stocks, preferred stocks, depositary receipts, warrants, securities convertible into common or preferred stocks and real estate investment trusts ("REITS")). The Fund may also invest up to 25% of its assets in publicly traded master limited partnerships ("MLPs"). The Fund may invest in fixed-income securities (including exchange-traded notes, structured notes, corporate debt, foreign and U.S. government and agency fixed-income securities, bank loans, adjustable floating rate loans and other floating rate debt instruments issued by U.S. and non-U.S. corporations and other business entities and convertible debt securities). The Fund may invest in below investment grade fixed-income securities (commonly known as "junk bonds"). Below investment grade fixed-income securities are rated below investment grade quality (i.e., none of the three major ratings agencies (Moody's Investors Service, Inc. ("Moody's"), Fitch Investors Services, Inc. ("Fitch") or Standard and Poor's Ratings Group ("S&P")), have rated the securities in one of its top four rating categories) or, if unrated, are determined by Loomis Sayles & Company, L.P. ("Loomis Sayles" or the "Subadviser") to be of comparable quality. There is no minimum rating for the fixed-income securities in which the Fund may invest. The Fund may invest in securities of any maturity or market capitalization. The Fund may invest in foreign securities including those in emerging markets.

The Fund may shift its assets among various types of income-producing securities based upon the Subadviser's evaluation of changing market conditions, yield expectations and security-specific opportunities. Changes to the Fund's asset allocations are based on several criteria, including global market cycles, global economic regimes and the relative attractiveness of particular asset categories. Under normal market conditions, the Fund will typically invest between 20% and 80% of its assets in fixed-income securities and between 30% and 70% in equity securities. However, the Fund is not required to allocate its investments among asset classes in any fixed proportion and may invest up to 100% of its assets in either equity securities or fixed-income securities. A sudden change in market conditions could cause the Subadviser to substantially change the allocation of the Fund's assets over a relatively short period of time.

In selecting individual investments for the Fund, the Subadviser considers factors including, but not limited to, economic and business cycles as well as top-down sector valuations and fundamental, bottom-up security valuations. In deciding which equity securities to buy and sell, the Subadviser seeks to identify securities that it believes are, among other things, attractively valued based on the Subadviser's estimate of what a security is actually worth, with additional consideration given to income-producing securities.

In deciding which fixed-income securities to buy and sell, the Subadviser may consider a number of factors including, but not limited to, diverging business cycles among countries and regions, the stability and volatility of a country's bond markets, the financial strength of the issuer, current interest rates, the Subadviser's expectations regarding general trends in interest rates and currency considerations. The Subadviser will also consider how purchasing or selling a security would impact the overall portfolio's risk profile (for example, its sensitivity to currency risk, interest rate risk and sector-specific risk) and potential return (income and capital gains).

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Fund Summary

When constructing the Fund's portfolio the Subadviser will use risk management tools in an effort to manage risk on an ongoing basis. These tools include the use of models that evaluate risk correlation to various market factors or asset classes, scenario analysis to measure the impact of certain market events and measuring the volatility of certain sectors and securities to understand the level of risk being contributed by these sectors and securities. The portfolio management team expects to actively evaluate each investment idea and to decide to buy or sell an investment based upon: (i) its return potential; (ii) its level of risk; and (iii) its fit within the team's overall macro strategy, with the goal of continually optimizing the Fund's portfolio.

The Fund may also:

• Invest in mortgage-related and asset-backed securities

• Invest in securities offered in initial public offerings ("IPOs") and securities issued pursuant to Rule 144A under the Securities Act of 1933 ("Rule 144A securities"). Rule 144A securities are privately offered securities and can be resold only to certain qualified institutional buyers.

• Engage in over-the-counter ("OTC") options, swap contracts (including credit default swaps) and currency transactions as well as futures transactions and other derivatives for hedging and investment purposes. The Fund may take both long and short positions in derivatives.

• Engage in active and frequent trading of securities and other instruments. Effects of frequent trading may include high transaction costs, which may lower the Fund's returns, and realization of short-term capital gains, distributions of which are taxable to shareholders who are individuals as ordinary income. Trading costs and tax effects associated with frequent trading may adversely affect the Fund's performance.

Principal Investment Risks

The principal risks of investing in the Fund are summarized below. The Fund does not represent a complete investment program. You may lose money by investing in the Fund.

Allocation Risk: The Fund's investment performance depends on how its assets are allocated. The allocation may not be optimal in every market condition. You could lose money on your investment in the Fund as a result of this allocation.

Credit/Counterparty Risk: Credit risk is the risk that the issuer or the guarantor of a fixed-income security, or the counterparty to a derivatives or other transaction, will be unable or unwilling to make timely payments of interest or principal or to otherwise honor its obligations. The Fund will be subject to credit risks with respect to the counterparties of its derivative transactions. Many of the protections afforded to participants on organized exchanges, such as the performance guarantee of an exchange clearing house, are not available in connection with OTC derivative transactions, such as OTC options. As a result, in instances when the Fund enters into OTC derivative transactions, the Fund will be subject to the risk that its counterparties will not perform their obligations under the transactions and that the Fund will sustain losses or be unable to realize gains.

Derivatives Risk: Derivative instruments (such as those in which the Fund may invest, including options, foreign currency transactions, futures transactions and swap transactions) are subject to changes in the value of the underlying assets or indices on which such instruments are based. There is no guarantee that the use of derivatives will be effective or that suitable transactions will be available. Even a small investment in derivatives may give rise to leverage risk and can have a significant impact on the Fund's exposure to securities markets values, interest rates or currency exchange rates. It is possible that the Fund's liquid assets may be insufficient to support its obligations under its derivatives positions. The use of derivatives for other than hedging purposes may be considered a speculative activity, and involves greater risks than are involved in hedging. The use of derivatives may cause the Fund to incur losses greater than those that would have occurred had derivatives not been used. The Fund's use of derivatives involves other risks, such as the credit risk relating to the other party to a derivative contract (which is greater for forward currency contracts, swaps and other OTC traded derivatives), the risk of difficulties in pricing and valuation, the risk that changes in the value of a derivative may not correlate as expected with changes in the value of relevant assets, rates or indices, liquidity risk, allocation risk and the risk of losing more than the initial margin required to initiate derivatives positions. There is also the risk that the Fund may be unable to terminate or sell a derivatives position at an advantageous time or price. The Fund's derivative counterparties may experience financial difficulties or otherwise be unwilling or unable to honor their obligations, possibly resulting in losses to the Fund. 

Equity Securities Risk: The value of the Fund's investments in equity securities could be subject to unpredictable declines in the value of individual securities and periods of below-average performance in individual securities or in the equity market as a whole. Securities issued in IPOs tend to involve greater market risk than other equity securities due, in part, to public perception and the lack of publicly available information and trading history. Rule 144A securities may be less liquid than other equity securities. In the event an issuer is liquidated or declares bankruptcy, the claims of owners of the issuer's bonds generally take precedence over the claims of those who own preferred stock or common stock.

Fixed-Income Securities Risk: Fixed-income securities are subject to credit risk, interest rate risk and liquidity risk. You may lose money on your investment due to unpredictable drops in a security's value or periods of below-average performance in a given security or in the securities market as a whole.

Foreign Securities Risk: Investments in foreign securities may be subject to greater political, economic, environmental, credit and information risks. The Fund's investments in foreign securities also are subject to foreign currency fluctuations and other foreign currency-related risks. Foreign securities may be subject to higher volatility than U.S. securities, varying degrees of regulation and limited liquidity.

Interest Rate Risk: Interest rate risk is the risk that the value of the Fund's investments will fall if interest rates rise. Generally, the value of fixed-income securities rises when prevailing interest rates fall and falls when interest rates rise. Interest rate risk generally is greater for funds that invest in fixed-income securities with relatively longer durations than for funds that invest in fixed-income securities with shorter durations. In addition, an economic downturn or

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Fund Summary

period of rising interest rates could adversely affect the markets for these securities and reduce the Fund's ability to sell them, negatively impacting the performance of the Fund.

Leverage Risk: Use of derivative instruments may involve leverage.  Leverage is the risk associated with securities or practices that multiply small index, market or asset-price movements into larger changes in value. The use of leverage increases the impact of gains and losses on a fund's returns, and may lead to significant losses if investments are not successful.

Liquidity Risk: Liquidity risk is the risk that the Fund may be unable to find a buyer for its investments when it seeks to sell them or to receive the price it expects. Decreases in the number of financial institutions willing to make markets in the Funds' investments or in their capacity or willingness to transact may increase the Funds' exposure to this risk. Events that may lead to increased redemptions, such as market disruptions or increases in interest rates, may also negatively impact the liquidity of the Fund's investments when it needs to dispose of them. If the Fund is forced to sell its investments at an unfavorable time and/or under adverse conditions in order to meet redemption requests, such sales could negatively affect the Fund. Securities acquired in a private placement, such as Rule 144A securities, are generally subject to greater liquidity risk because they are subject to strict restrictions on resale and there may be no liquid secondary market or ready purchaser for such securities. Non-exchange traded derivatives are generally subject to greater liquidity risk as well. Liquidity issues may also make it difficult to value the Fund's investments.

Management Risk: A strategy used by the Fund's portfolio managers may fail to produce the intended result.

Master Limited Partnership Risk: Investments in MLPs involve risks in addition to the risks associated with investments in securities with similar characteristics, such as common stock of a corporation. Holders of common interests in MLPs typically have limited control and limited rights to vote on matters affecting the MLP. Conflicts of interest may also exist between an MLP's common interest holders and its general partner or managing member, including those arising from incentive distribution payments. Many interests in MLPs are subject to restrictions on resale and may therefore be less liquid than other investments, which may subject MLP interests to more abrupt or erratic price movements and may increase the difficulty of disposing of such interests at favorable times and prices. The Fund may gain exposure to MLPs through derivatives, including exchange-traded notes ("ETNs") and swaps, exposing the Fund to the risks of investing in derivatives generally. MLPs often own interests in energy infrastructure properties, including pipelines, or engage in activities related to the energy sector. Accordingly, to the extent the Fund invests in MLPs, it will likely be exposed to risks related to investments in the energy sector. In addition, if an MLP fails to meet the current legal requirements for treatment as a partnership, or if there are changes to the tax laws, an MLP could be treated as a corporation for U.S. federal income tax purposes, obligating the MLP to pay tax at the entity level and significantly reducing the income to the Fund from an investment in an MLP.

Market Risk: The market value of a security or portfolio will move up and down, sometimes rapidly and unpredictably, based upon a change in an issuer's financial condition, as well as overall market and economic conditions.

Mortgage-Related and Asset-Backed Securities Risk: In addition to the risks associated with investments in fixed-income securities generally (for example, credit, liquidity and valuation risk), mortgage-related and asset-backed securities are subject to the risks of the mortgages and assets underlying the securities as well as prepayment risk, the risk that the securities may be prepaid and result in the reinvestment of the prepaid amounts in securities with lower yields than the prepaid obligations. Conversely, there is a risk that a rise in interest rates will extend the life of a mortgage-related or asset-backed security beyond the expected prepayment time, typically reducing the security's value. The Fund also may incur a loss when there is a prepayment of securities that were purchased at a premium. The Fund's investments in other asset-backed securities are subject to risks similar to those associated with mortgage-related securities, as well as additional risks associated with the nature of the assets and the servicing of those assets.

REITs Risk:  Investments in the real estate industry, including REITs, are particularly sensitive to economic downturns and are sensitive to factors such as changes in real estate values, property taxes and tax laws, interest rates, cash flow of underlying real estate assets, occupancy rates, government regulations affecting zoning, land use and rents and the management skill and creditworthiness of the issuer. Companies in the real estate industry also may be subject to liabilities under environmental and hazardous waste laws. In addition, the value of a REIT is affected by changes in the value of the properties owned by the REIT or mortgage loans held by the REIT. REITs are also subject to default and prepayment risk. Many REITs are highly leveraged, increasing their risk. The Fund will indirectly bear its proportionate share of expenses, including management fees, paid by each REIT in which it invests in addition to the expenses of the Fund.

Small- and Mid-Capitalization Companies Risk: Compared to large-capitalization companies, small- and mid-capitalization companies are more likely to have limited product lines, markets or financial resources. Stocks of these companies often trade less frequently and in limited volume and their prices may fluctuate more than stocks of large-cap companies. As a result, it may be relatively more difficult for the Fund to buy and sell securities of small- and mid-cap companies.

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Fund Summary

Risk/Return Bar Chart and Table

The bar chart and table shown below provide some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual returns for the one-year, five-year and Life-of-Class periods compare to those of a broad measure of market performance. The Fund's past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Updated performance information is available online at ngam.natixis.com and/or by calling the Fund toll-free at 800-225-5478.

The chart does not reflect any sales charge that you may be required to pay when you buy or redeem the Fund's shares. A sales charge will reduce your return.

Total Returns for Class A Shares

Highest Quarterly Return:
Second Quarter 2009, 18.28%


Lowest Quarterly Return:
Fourth Quarter 2008, -18.23%

Average Annual Total Returns
(for the periods ended December 31, 2014)	Past 1 Year		Past 5 Years		Life-of- Class (11/17/05)		Life-of- Class Y (12/3/12)
Class A - Return Before Taxes 1	8.30	%	10.18	%	6.77	%	-
Return After Taxes on Distributions 1	7.29	%	9.14	%	5.54	%	-
Return After Taxes on Distributions and Sale of Fund Shares 1	4.88	%	7.69	%	4.90	%	-
Class C - Return Before Taxes	11.28	%	10.31	%	6.47	%	-
Class Y - Return Before Taxes	13.05	%	11.16	% 2	-		9.78	%
Barclays U.S. Aggregate Bond Index	5.97	%	4.45	%	5.00	%	1.77	%

¹ The maximum sales charge on purchases of Class A shares was reduced from 4.50% to 4.25% on November 2, 2015. The Fund's returns for Class A shares for all periods have been restated to reflect the current maximum applicable sales charge of 4.25%.

² Prior to the inception of Class Y shares (12/3/12), performance is that of Class A shares and reflects the higher net expenses of that share class.

The Fund did not have Class N shares outstanding during the periods shown above. The returns of Class N shares would have been substantially similar to the returns of the Fund's other share classes because they would have been invested in the same portfolio of securities and would only differ to the extent the other share classes did not have the same expenses.

Prior to the stock market close August 31, 2015, the Fund had multiple subadvisers. The performance results shown above for the periods prior to the stock market close August 31, 2015 reflect results achieved by those subadvisers using different investment strategies.

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-advantaged arrangements, such as 401(k) plans, qualified plans, education savings accounts, such as 529 plans or individual retirement accounts. The after-tax returns are shown for only one class of the Fund. After-tax returns for the other classes of the Fund will vary. Index performance reflects no deduction for fees, expenses or taxes.

Management

Investment Adviser

NGAM Advisors, L.P. ("NGAM Advisors")

Subadviser

Loomis, Sayles & Company, L.P. ("Loomis Sayles")

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Fund Summary

Portfolio Managers

Thomas Fahey, Vice President of Loomis Sayles, has served as a co-manager of the Fund since 2015.

Kevin P. Kearns, Vice President of Loomis Sayles, has served as a co-manager of the Fund since 2012.

Maura T. Murphy, CFA^®, Vice President of Loomis Sayles, has served as a co-manager of the Fund since 2012.

Purchase and Sale of Fund Shares

Class A and C Shares

The following chart shows the investment minimums for various types of accounts:

Type of Account	Minimum Initial Purchase		Minimum Subsequent Purchase
Any account other than those listed below	$	2,500	$	100
For shareholders participating in Natixis Funds' Investment Builder Program	$	1,000	$	50
For Traditional IRA, Roth IRA, Rollover IRA, SEP-IRA and Keogh plans using the Natixis Funds' prototype document (direct accounts, not held through intermediary)	$	1,000	$	100
Coverdell Education Savings Accounts using the Natixis Funds' prototype document (direct accounts, not held through intermediary)	$	500	$	100

Class N Shares

Class N shares of the Fund are subject to a $1,000,000 initial investment minimum. There is no initial investment minimum for employer-sponsored retirement plans held in an omnibus fashion and fund of funds that are distributed by NGAM Distribution, L.P. (the "Distributor"). There is no subsequent investment minimum for these shares.

Class Y Shares

Class Y shares of the Fund may be purchased by the following entities at the following investment minimums.

A minimum initial investment of $100,000 and the minimum subsequent investment of $100 for:

■

Other mutual funds, endowments, foundations, bank trust departments or trust companies.

There is no initial or subsequent investment minimum for:

■

Wrap Fee Programs of certain broker-dealers, the adviser or the Distributor. Please consult your financial representative to determine if your wrap fee program is subject to additional or different conditions or fees.

■

Retirement Plans such as 401(a), 401(k) or 457 plans.

■

Certain Individual Retirement Accounts if the amounts invested represent rollover distributions from investments by any of the retirement plans invested in the Fund.

■

Registered Investment Advisers investing on behalf of clients in exchange for an advisory, management or consulting fee.

■

Fund Trustees, former Fund trustees, employees of affiliates of the Natixis Funds and other individuals who are affiliated with any Natixis Fund (this also applies to any spouse, parents, children, siblings, grandparents, grandchildren and in-laws of those mentioned) and Natixis affiliate employee benefit plans.

Due to operational limitations at your financial intermediary, certain wrap fee programs, retirement plans, individual retirement accounts and accounts of registered investment advisers may be subject to the investment minimums described above.

The Fund's shares are available for purchase and are redeemable on any business day through your investment dealer, directly from the Fund by writing to the Fund at Natixis Funds, P.O. Box 219579, Kansas City, MO 64121-9579, by exchange, by wire, by internet at ngam.natixis.com, through the Automated Clearing House system, or, in the case of redemptions, by telephone at 800-225-5478 or by the Systematic Withdrawal Plan. 

Tax Information

Fund distributions are generally taxable to you as ordinary income or capital gains, except for distributions to retirement plans and other investors that qualify for tax-exempt treatment under U.S. federal income tax law generally. Investments in such tax-advantaged plans will generally be taxed only upon withdrawal of monies from the tax-exempt arrangement.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase shares of the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of the Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other

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Fund Summary

intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary's website for more information.

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UMI77-1115