Researchers have introduced a new mathematical model called DAMM (Digestion, Absorption, and Microbial Metabolism) that tracks how gut bacteria influence calorie absorption from food, challenging the 130-year-old Atwater formula. In a controlled trial involving 17 participants, DAMM demonstrated a 96% accuracy rate in predicting calorie absorption, compared to 88% for the Atwater method. The Atwater formula has been found to underestimate calorie absorption, particularly in individuals consuming a Western diet, due to its failure to account for short-chain fatty acids produced by gut bacteria when fiber intake is low.
The study, conducted by scientists at Arizona State University and AdventHealth Translational Research Institute and published in the journal PLOS ONE, involved participants consuming two distinct diets: one high in fiber and resistant starch, and another typical Western diet low in fiber. Researchers measured energy absorption through fecal samples and methane gas production, revealing that the DAMM model significantly improved predictions of energy absorption compared to the Atwater formula.
Additionally, the study found that some methane-producing gut microbes may reside in biofilms along the intestinal wall, which could lead to undercounting their populations in standard microbiome tests. The findings suggest that variations in gut microbiome composition may explain why dietary effects differ among individuals.
