TY - JOUR
T1 - Developing a model for estimating the activity of colonic microbes after intestinal surgeries
AU - Marcus, Andrew
AU - Davis, Taylor L.
AU - Rittmann, Bruce E.
AU - DiBaise, John K.
AU - Carnero, Elvis A.
AU - Corbin, Karen
AU - Smith, Steven R.
AU - Krajmalnik-Brown, Rosa
N1 - Publisher Copyright:
Copyright: © 2021 Marcus et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PY - 2021/7
Y1 - 2021/7
N2 - Background The large intestine provides a compensatory role in energy recovery when surgical interventions such as extensive small intestinal resections or bypass operations lower the efficiency of nutrient absorption in the upper gastrointestinal (GI) tract. While microorganisms in the colon are known to play vital roles in recovering energy, their contributions remain to be qualified and quantified in the small intestine resection. Objective We develop a mathematical model that links nutrient absorption in the upper and lower GI tract in two steps. Methods First, we describe the effects of small intestine resection on the ileocecal output (ICO), which enters the colon and provides food for microbes. Second, we describe energy recovered by the colon’s microorganisms via short-chain fatty acid (SCFA) production. We obtain model parameters by performing a least-squares regression analysis on clinical data for subjects with normal physiology and those who had undergone small intestine resection. Results For subjects with their intestines intact, our model provided a metabolizable energy value that aligns well with the traditional Atwater coefficients. With removal of the small intestine, physiological absorption became less efficient, and the metabolizable energy decreased. In parallel, the inefficiencies in physiological absorption by the small intestine are partly compensated by production of short-chain fatty acids (SCFA) from proteins and carbohydrates by microorganisms in the colon. The colon recovered more than half of the gross energy intake when the entire small intestine was removed. Meanwhile, the quality of energy absorbed changed, because microbe-derived SCFAs, not the original components of food, become the dominant form of absorbed energy. Conclusion The mathematical model developed here provides an important framework for describing the effect of clinical interventions on the colon’s microorganisms.
AB - Background The large intestine provides a compensatory role in energy recovery when surgical interventions such as extensive small intestinal resections or bypass operations lower the efficiency of nutrient absorption in the upper gastrointestinal (GI) tract. While microorganisms in the colon are known to play vital roles in recovering energy, their contributions remain to be qualified and quantified in the small intestine resection. Objective We develop a mathematical model that links nutrient absorption in the upper and lower GI tract in two steps. Methods First, we describe the effects of small intestine resection on the ileocecal output (ICO), which enters the colon and provides food for microbes. Second, we describe energy recovered by the colon’s microorganisms via short-chain fatty acid (SCFA) production. We obtain model parameters by performing a least-squares regression analysis on clinical data for subjects with normal physiology and those who had undergone small intestine resection. Results For subjects with their intestines intact, our model provided a metabolizable energy value that aligns well with the traditional Atwater coefficients. With removal of the small intestine, physiological absorption became less efficient, and the metabolizable energy decreased. In parallel, the inefficiencies in physiological absorption by the small intestine are partly compensated by production of short-chain fatty acids (SCFA) from proteins and carbohydrates by microorganisms in the colon. The colon recovered more than half of the gross energy intake when the entire small intestine was removed. Meanwhile, the quality of energy absorbed changed, because microbe-derived SCFAs, not the original components of food, become the dominant form of absorbed energy. Conclusion The mathematical model developed here provides an important framework for describing the effect of clinical interventions on the colon’s microorganisms.
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U2 - 10.1371/journal.pone.0253542
DO - 10.1371/journal.pone.0253542
M3 - Article
C2 - 34319981
AN - SCOPUS:85111574327
SN - 1932-6203
VL - 16
JO - PloS one
JF - PloS one
IS - 7 July
M1 - e0253542
ER -