Metabarcoding reveals that a non-nutritive sweetener and sucrose yield similar gut microbiota patterns in Wistar rats

Abstract The effects of non-nutritive sweeteners (NNS) on the gut microbiota are an area of increasing research interest due to their potential influence on weight gain, insulin resistance, and inflammation. Studies have shown that mice and rats fed saccharin develop weight gain and metabolic alterations, possibly related to changes in gut microbiota. Here, we hypothesized that chronic exposure to a commercial NNS would change the gut microbiota composition in Wistar rats when compared to sucrose exposure. To test this hypothesis, Wistar rats were fed either NNS- or sucrose-supplemented yogurt for 17 weeks alongside standard chow (ad libitum). The gut microbiome was assessed by 16S rDNA deep sequencing. Assembly and quantification were conducted using the Brazilian Microbiome Project pipeline for Ion Torrent data with modifications. Statistical analyses were performed in the R software environment. We found that chronic feeding of a commercial NNS-sweetened yogurt to Wistar rats, within the recommended dose range, did not significantly modify gut microbiota composition in comparison to sucrose-sweetened yogurt. Our findings do not support the hypothesis that moderate exposure to NNS is associated with changes in gut microbiota pattern compared to sucrose, at least in this experimental model.

摘要 非营养甜味剂（non-nutritive sweeteners, NNS）对肠道菌群（gut microbiota）的影响是当前研究的热点领域，因其可能对体重增加、胰岛素抵抗及炎症反应产生潜在影响。已有研究显示，喂食糖精的小鼠与大鼠会出现体重增加与代谢异常，该现象可能与肠道菌群的改变相关。本研究提出假说：与蔗糖暴露组相比，长期暴露于商用非营养甜味剂会改变Wistar大鼠的肠道菌群组成。为验证该假说，本研究将Wistar大鼠分为两组，分别喂食添加商用非营养甜味剂或蔗糖的酸奶，并伴随自由采食的标准饲料，干预时长共计17周。通过16S rDNA深度测序对肠道微生物组进行评估，序列组装与定量分析采用经改良的巴西微生物组项目（Brazilian Microbiome Project）针对Ion Torrent测序数据的分析流程完成，统计分析均在R软件环境中开展。本研究发现，在推荐剂量范围内，长期喂食商用非营养甜味剂调味酸奶的Wistar大鼠，其肠道菌群组成与蔗糖调味酸奶组相比无显著变化。本研究结果不支持“与蔗糖暴露相比，适度接触非营养甜味剂会导致肠道菌群模式改变”这一假说，至少在本实验模型中是如此。