Small intestinal microbiota: the neglected stepchild needed for fat digestion and absorption

Abstract

Our recently published paper "Small Intestine Microbiota Regulate Digestive and Absorptive Adaptive Responses to Dietary Lipids" in Cell Host & Microbe explored the neglected small intestine microbiota and demonstrated its critical role as a regulator of fat digestion and absorption. This work generated the following important take home messages: 1) small intestinal microbes are particularly sensitive to high fat diets and turn on host processes regulating fat digestion and transport, 2) this action is very likely orchestrated by a consortium of microbes, each having different specific effects and targets, and 3) the actions of this consortium appear to be mediated by bacteria-derived small molecules or bioactive components. These findings are expected to provide insight into developing treatments for conditions of under- or over-nutrition. The goal of this addendum is to summarize our findings, address issues related to gut microbiota and gnotobiotic research specifically regarding technology and experimental design, discuss this work in the context of relevant literature, and lastly provide considerations for future research.

The impact of maternal and early life malnutrition on health: a diet-microbe perspective

“…The gut microbiota has been demonstrated to stimulate hepatic triglyceride production (lipogenesis) by activating the transcription factors, carbohydrate response element binding protein (ChREBP), and sterol response element binding protein (SREBP) [85]. Recently, a critical role of the, complex but less diverse, small intestine microbiota as a regulator of fat digestion and absorption has been identified [86,87]. These microbes appear to be essential for host adaptation to dietary lipid changes by regulating gut epithelial processes involved in their digestion and absorption.…”

Protein microspheres as structuring agents in lipids: potential for reduction of total and saturated fat in food products

“…Overconsumption of saturated fats is linked with some problems to the body, such as insulin sensitivity, dyslipidemia, obesity, hypertension, metabolic syndrome, and premature death 7,10,48–50 . It has been reported that many peoples suffer from metabolic syndrome 51 .…”

Potential correlation between carbohydrate‐active enzyme family 48 expressed by gut microbiota and the expression of intestinal epithelial AMP‐activated protein kinase β

“…This was consistent with previous results reporting that excessive accumulation of TMAO or lipid might also lead to health problems induced by intake of dietary trimethylamine-containing nutrients . In fact, the correlations between these indices and AMPK expression levels have been reported, which could be attributed to the fact that AMPK affects the activity of enzymes involved in food digestion or nutrient absorption, such as lipid metabolism, fatty acid oxidation, and protein biosynthesis (Chang & Martinez-Guryn, 2019;Woods et al, 2017;Xin et al, 2018).…”

“…The results with significantly higher values for these indices were observed in mice fed the red meat diet (RM group, p value <.05,Figure 1b), potentially leading to a higher risk of CVDs(Wu, Micha, & Mozaffarian, 2019). In fact, the correlations between these indices and AMPK expression levels have been reported, which could be attributed to the fact that AMPK affects the activity of enzymes involved in food digestion or nutrient absorption, such as lipid metabolism, fatty acid oxidation, and protein biosynthesis(Chang & Martinez-Guryn, 2019;Woods et al, 2017;Xin et al, 2018). In fact, the correlations between these indices and AMPK expression levels have been reported, which could be attributed to the fact that AMPK affects the activity of enzymes involved in food digestion or nutrient absorption, such as lipid metabolism, fatty acid oxidation, and protein biosynthesis(Chang & Martinez-Guryn, 2019;Woods et al, 2017;Xin et al, 2018).…”