(P06-036-25) Effects of Diets Containing High Fat and Ammoniated Beef on Composition of Gut Microbiota

Objectives: Diets high in fat and sodium, with limited fruits and vegetables, are often acidic and may contribute to metabolic dysfunctions, including acidosis. In our previous study in high fat (HF) diet-induced obese mice, we demonstrated metabolic benefits including reduced fat mass in males and improved glucose clearance in females, from consuming diets containing pH-enhanced beef diets (via ammonium hydroxide, N), compared to non-ammoniated diets. However, underlying mechanisms remain unknown. We hypothesized that modeling of gut microbiota by ammoniated diets is partly responsible for these observed protective effects.

Methods: Male and female B6 mice were fed one of four diets for 12 weeks: Low fat beef (LFB), LFB + N (LFBN), HF Beef (HFB), or HFB + N (HFBN) followed by terminal collection of tissues and fecal samples. We previously reported metabolic phenotyping of these mice. Here, we determined changes in gut microbiota composition by 16S sequencing of fecal DNA samples. Moreover, we determined changes in markers of intestinal barrier integrity, using qRT-PCR.

Results: Analyses of 16S sequencing revealed that in females, alpha diversity was significantly reduced in the HFBN group compared to LFBN (P=0.02), with no changes observed for males. Principal coordinate analysis (PCOA) of beta diversity revealed no clear clustering patterns for females. In males, clustering was observed based on dietary fat content but not ammoniation. At the family level, females unexpectedly exhibited a significant increase in the relative abundance of Bacteroidaceae in the HF, compared to the LF group (P=0.0044), while no significant changes were observed in males. In both males (P=0.0012) and females (P=0.047), the relative abundance of Muribaculaceae decreased significantly in the HF compared to LF group at the family level.

Conclusions: Our results demonstrate that while ammoniation led to some metabolic improvements in diet-induced obese mice, dietary fat content appears to be the primary modulator of gut microbiota composition. Ongoing analyses will determine whether changes in microbiota composition are associated with altered markers of gut integrity. Further research is warranted to uncover mechanisms connecting dietary fat, food processing, gut microbiota, and metabolic health.

Funding Sources: Funded by Empirical Foods Inc.