For captive primates, greater provisioning of leafy greens or foliage can promote natural foraging behavior while boosting fiber intake. Recalcitrant fiber, although minimally available to endogenous metabolism, is readily fermented into nutrients by gut microbes. Whereas most primates in captivity consume fiber-limited diets and harbor imbalanced gut microbiota compared to their wild conspecifics, the importance of fiber provisioning to primate gut microbiota has predominately been studied in folivores. We, therefore, determined if commercial lettuce could be used to encourage foraging behavior and modify the gut microbiota of captive frugivores. We provisioned ruffed lemurs (Varecia rubra and V. variegata) with romaine lettuce, on top of the standard dietary fare, for 10 consecutive days. Before and across the period of lettuce supplementation, we collected observational data of animal feeding and fecal samples for microbiome analysis, determined via amplicon sequencing. The ruffed lemurs and their gut microbes responded to lettuce provisioning. In particular, younger animals readily ate lettuce and showed no decline in consumption across study days. When controlling for the effects of host species and social-group membership, lettuce consumption shifted the composition of the gut microbiome away from each lemur's own baseline, an effect that became stronger as the study progressed. In the final study days, Ruminococcaceae UCG-008 and Akkermansia, microbes typically and respectively associated with fiber metabolism and host health, were significantly enriched in the consortia of lettuce-provisioned subjects. Ultimately, the routine offering of lettuce, leafy greens, or foliage to captive frugivores may benefit animal wellbeing.

中文翻译：

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每日生菜补充剂促进觅食行为并改变圈养食果动物的肠道微生物群

对于圈养灵长类动物，更多地提供绿叶蔬菜或树叶可以促进自然觅食行为，同时增加纤维摄入量。顽固的纤维虽然很少被内源性代谢利用，但很容易被肠道微生物发酵成营养物质。虽然圈养的大多数灵长类动物消耗纤维有限的饮食，并且与野生同种动物相比，肠道微生物群不平衡，但主要在食叶动物中研究了纤维对灵长类动物肠道微生物群的重要性。因此，我们确定是否可以使用商业生菜来鼓励觅食行为并改变圈养食果动物的肠道微生物群。我们在标准饮食之外连续 10 天为狐猴（Varecia rubra 和 V. variegata）提供长叶莴苣。在补充生菜之前和期间，我们收集了动物饲料和粪便样本的观察数据，用于微生物组分析，通过扩增子测序确定。皱褶狐猴及其肠道微生物对生菜供应做出反应。特别是，年轻的动物很容易吃生菜，并且在整个研究日内的消费量没有下降。在控制宿主物种和社会群体成员的影响时，食用生菜使肠道微生物组的组成偏离了每只狐猴自身的基线，随着研究的进行，这种影响变得越来越大。在最后的研究日中，瘤胃球菌科 UCG-008 和 Akkermansia（通常分别与纤维代谢和宿主健康相关的微生物）在提供生菜的受试者群中显着丰富。最终，生菜、绿叶蔬菜、