Omega-3 (n-3) polyunsaturated fatty acids (PUFAs), particularly docosahexaenoic acid (DHA), are required for the structure and function of the retina. Several observational studies indicate that consumption of a diet with relatively high levels of n-3 PUFAs, such as those provided by fish oils, has a protective effect against the development of age-related macular degeneration. Given the accumulating evidence showing the role of gut microbiota in regulating retinal physiology and host lipid metabolism, we evaluated the potential of long-term dietary supplementation with the Gram-positive bacterium Lactobacillus helveticus strain VEL12193 to modulate the retinal n-3 PUFA content. A set of complementary approaches was used to study the impact of such a supplementation on the gut microbiota and host lipid/fatty acid (FA) metabolism. L. helveticus-supplementation was associated with a decrease in retinal saturated FAs (SFAs) and monounsaturated FAs (MUFAs) as well as an increase in retinal n-3 and omega-6 (n-6) PUFAs. Interestingly, supplementation with L. helveticus enriched the retina in C22:5n-3 (docosapentaenoic acid, DPA), C22:6n-3 (DHA), C18:2n-6 (linoleic acid, LA) and C20:3n-6 (dihomo gamma-linolenic acid, DGLA). Long-term consumption of L. helveticus also modulated gut microbiota composition and some changes in OTUs abundance correlated with the retinal FA content. This study provides a proof of concept that targeting the gut microbiota could be an effective strategy to modulate the retinal FA content, including that of protective n-3 PUFAs, thus opening paths for the design of novel preventive and/or therapeutical strategies for retinopathies.

Omega-3 (n-3) 多不饱和脂肪酸 (PUFA)，特别是二十二碳六烯酸 (DHA)，是视网膜的结构和功能所必需的。多项观察性研究表明，食用 n-3 PUFA 含量相对较高的饮食（例如鱼油提供的食物）对预防年龄相关性黄斑变性的发展具有保护作用。鉴于越来越多的证据表明肠道微生物群在调节视网膜生理和宿主脂质代谢中的作用，我们评估了长期膳食补充革兰氏阳性菌瑞士乳杆菌菌株 VEL12193 调节视网膜 n-3 PUFA 含量的潜力。使用一组补充方法来研究这种补充剂对肠道微生物群和宿主脂质/脂肪酸（FA）代谢的影响。补充瑞士乳杆菌与视网膜饱和 FA (SFA) 和单不饱和 FA (MUFA) 减少以及视网膜 n-3 和 omega-6 (n-6) PUFA 增加相关。有趣的是，补充瑞士乳杆菌可丰富视网膜中的 C22:5n-3（二十二碳五烯酸，DPA）、C22:6n-3（DHA）、C18:2n-6（亚油酸，LA）和 C20:3n-6（二高γ-亚麻酸，DGLA)。长期食用瑞士乳杆菌还调节肠道微生物群组成以及与视网膜 FA 含量相关的 OTU 丰度的一些变化。这项研究提供了一个概念证明，即针对肠道微生物群可能是调节视网膜 FA 含量（包括保护性 n-3 PUFA 含量）的有效策略，从而为设计新的视网膜病预防和/或治疗策略开辟了道路。