Personalized nutrition, microbiota, and metabolism: A triad for eudaimonia

 Front. Mol. Biosci., 2022

During the previous few years, the relationship between the gut microbiota, metabolic disorders, and diet has come to light, especially due to the understanding of the mechanisms that particularly link the gut microbiota with obesity in animal models and clinical trials. Research has led to the understanding that the responses of individuals to dietary inputs vary remarkably therefore no single diet can be suggested to every individual. The variations are attributed to differences in the microbiome and host characteristics. In general, it is believed that the immanent nature of host-derived factors makes them difficult to modulate. However, diet can more easily shape the microbiome, potentially influencing human physiology through modulation of digestion, absorption, mucosal immune response, and the availability of bioactive compounds. Thus, diet could be useful to influence the physiology of the host, as well as to ameliorate various disorders. In the present study, we have described recent developments in understanding the disparities of gut microbiota populations between individuals and the primary role of diet-microbiota interactions in modulating human physiology. A deeper understanding of these relationships can be useful for proposing personalized nutrition strategies and nutrition-based therapeutic interventions to improve human health.

Metabolomics approach reveals high energy diet improves the quality and enhances the flavor of black Tibetan sheep meat by altering the composition of rumen microbiota

 Front. Nut. 2022

This study aims to determine the impact of dietary energy levels on rumen microbial composition and its relationship to the quality of Black Tibetan sheep meat by applying metabolomics and Pearson's correlation analyses. For this purpose, UHPLC-QTOF-MS was used to identify the metabolome, whereas 16S rDNA sequencing was used to detect the rumen microbiota. Eventually, we observed that the high energy diet group (HS) improved the carcass quality of Black Tibetan sheep and fat deposition in the longissimus lumborum (LL) compared to the medium energy diet group (MS). However, HS considerably increased the texture, water holding capacity (WHC), and volatile flavor of the LL when compared to that of MS and the low energy diet group (LS). Metabolomics and correlation analyses revealed that dietary energy levels mainly affected the metabolism of carbohydrates and lipids of the LL, which consequently influenced the content of volatile flavor compounds (VOCs) and fats. Furthermore, HS increased the abundance of Quinella, Ruminococcus 2, (Eubacterium) coprostanoligenes, and Succinivibrionaceae UCG-001, all of which participate in the carbohydrate metabolism in rumen and thus influence the metabolite levels (stachyose, isomaltose, etc.) in the LL. Overall, a high-energy diet is desirable for the production of Black Tibetan sheep mutton because it improves the mouthfeel and flavor of meat by altering the composition of rumen microbiota, which influences the metabolism in the LL.

Dietary polyphenols for managing cancers: What have we ignored?

 Trends in Food Science & Technology, 2020, 101, 150-164

DOI: 10.1016/j.tifs.2020.05.017

Although the chemoprevention and anti-cancer activities of dietary polyphenols have been evidenced through both in vitro and in vivo studies, most of the human clinical trials were unsuccessful or even harmful. Debates on the beneficial roles of dietary polyphenols in cancer therapy are increasing. Many dietary polyphenols studies are conducted by in vitro experiments, but the nature of these studies does not consider the complexity of metabolic processes that are present in vivo. These can often cause instability in the dietary polyphenols, thereby leading to unsuccessful extrapolation into animal or human studies. Dietary polyphenols often have low bioavailability, which is mainly due to poor bioaccessibility and significant metabolism mediated by both host enzymes and colon microbiota. Some metabolites or catabolites are more potent and absorb better than the parent component. It is recognised that the oral bioavailability of dietary polyphenols is underestimated when the bioactive metabolites or catabolites are not considered. Notably, dietary polyphenols and their metabolites undergo further cellular metabolism within the cancer cells, which confers “cellular bioavailability” as an additional step to influence the actions of dietary polyphenols. Moreover, there are growing controversies in using dietary polyphenols for both chemopreventive and anti-cancer applications. A clear therapeutic window for dietary polyphenols as specific chemopreventive or chemotherapeutic agents is required. This review, thus, aims to identify key issues that were ignored by most of the studies, or are critical for future investigation.