-There are several factors affect the composition of Human GI microbiota such as : genetics
,sex,ethnicity , age, medications , diseasesdisorder and last but not least THE
-Fat accumulation especially Visceral fat have been found to be linked with microbiota , but
still its relative contribution has not been well characterized,(Le Roy, et al ,2019).
-Recently, it has been proposed that physical exercise is able to modify gut microbiota , and
thus this could be another factor by which exercise promotes well-being, since gut microbiota
appears to be closely related to health and disease,(Cerda’,et al, 2016).
Various location of Human Microbiome
The Human Microbiome
Oral Cavity Nasal cavity Genito-Urinery tract
Figure1 : A line diagram indicating various locations
of human microbiome. (kumar, et al ,2017).
Does Diet Matter ?
-Diet Can shape the composition of microbiota ,(Le Roy, et al ,2019).
-They study the diet as a factor contributing to host-microbe symbiosis, by driving
the production of gut microbe-derived bioactive metabolites, by identify metabolic
*Gut microbes produce :
1-short chain fatty acids by fermentation of the undigested dietary foods.
2- Menaquinone, folate , cobalamine and riboflavin to fulfil their own energetic
and metabolic requirements and they act as vitamins (vitamins K,B9,B12,and B2 ,
-Short chain fatty acids are used by host cells as signaling molecules or substrates
-SCFA have distinct physiological effects: they contribute to shaping the gut
environment, influence the physiology of the colon ,they can be used as energy
sources by host cells and the intestinal microbiota and they also participate in
different host-signaling mechanisms (covian , et al , 2016).
-Vitamin K plays a key role in blood coagulation , bone metabolism , and possibly ,
insulin sensitivity (DiNicolantonio, J,J.et al. 2015).
-Vitamin B9 is an essential vitamin involved in cell division , and a deficiency of this
vitamin is associated with higher risk of cancer , anaemia, and neural tube defects
-Vitamin B12 is a metabolic co-factor , deficiencies of which led to increase in the
risks of dementia in the elderly and cardiovascular diseases (Woo,K.S.et al , 2014).
-Vitamin B2 is a precursor for the cofactors flavin adenine dinucleotide (FAD) and
flavin mono-nucleotide (FMN). Its deficiency is associated with neuromuscular and
neurological disorders, cancer and predisposition of Listeria infection (Schramm, M. et
-Several studies using animals models have shown that microbes alone can trigger obesity-
associated phenotypes and that diet alone may not be necessary to observe such effect
(Ridaura, V.K. et al 2013).
-Understanding the contribution of the gut microbiome in diet induced host adiposity is key
towards an improved management of the obesity pandemic. Therefore there is a need to
understand the extent to which diet and the gut microbiota affect host adiposity
synergistically or independently (Le Roy ,et al ,2019).
-Thus diet and the gut microbiota may synergistically affect host VFM (visceral fat mass ).
-In human faecal Microbiota transplantation from lean donors has successfully improved
insulin sensitivity in obese recipitants.
-Additionally probiotic interventions in humans have also demonstrated the potential of
administering a single microbial organism to affect host adiposity (Borgeraas, et al , 2018).
-Final result : that four nutrients : fibre, vitamin E, magnesium and biotin are most likely to
require gut microbiota mediation to affect VFM accumulation (Le Roy ,et al ,2019).
-In recent years, a new factor by which exercise may
promote beneficial health effects has emerged : the
modification of gut microbiota (Cerda’, et al 2016).
-A changes showed in the composition of the microbiota in
mice which preformed exercise vs. sedentary mice. A total
beneficial bacterial have been found in the exercise group
more than sedentary group (Choi et al., 2013)
Diets poor in microbiota-accessible carbohydrates are known to have profound effects on the gut
microbiota, (Liyod-Price, J. et al,2016).
-The use of antibiotics will directly affect the balance of your gut microbiota.
-The bacterial genes required for vitamin production are now well documented (LeBlanc, J,G, et al,
2013).It should therefore be possible to explore the role of gut microbiota and probiotics as vitamin
suppliers in more detail (Derrien,Veiga, 2017).
-The dietary interventions aiming to improve host metabolism might be improved by also targeting
the gut microbiota (Le Roy ,et al ,2019).
12. References :
-Boulangé, Claire L., et al. "Impact of the gut microbiota on inflammation, obesity, and metabolic
disease." Genome medicine 8.1 (2016): 1-12.
-Agustí, Ana, et al. "Interplay between the gut-brain axis, obesity and cognitive function." Frontiers
in neuroscience 12 (2018): 155.
-Cerdá, Begoña, et al. "Gut microbiota modification: another piece in the puzzle of the benefits of
physical exercise in health?." Frontiers in physiology 7 (2016): 51.
-Davis, Cindy D. "The gut microbiome and its role in obesity." Nutrition today 51.4 (2016): 167.
-Kumar, A., and N. Chordia. "Role of microbes in human health." Appl Microbiol 3 (2017): 2-4.
-Integrative, H. M. P. "The Integrative Human Microbiome Project: dynamic analysis of microbiome-
host omics profiles during periods of human health and disease." Cell host & microbe 16.3 (2014):
-Le Roy, Caroline I., et al. "Dissecting the role of the gut microbiota and diet on visceral fat mass
accumulation." Scientific reports 9.1 (2019): 9758.
-Holmes, Andrew J., et al. "Diet-microbiome interactions in health are controlled by intestinal
nitrogen source constraints." Cell metabolism 25.1 (2017): 140-151.
13. References :
-Angelakis, Emmanouil, and Didier Raoult. "Gut microbiota modifications and weight gain in early
life." Human Microbiome Journal 7 (2018): 10-14.
-Wang, Yulan, et al. "Modulation of gut microbiota in pathological states." Engineering 3.1 (2017): 83-89.
-Derrien, Muriel, and Patrick Veiga. "Rethinking diet to aid human–microbe symbiosis." Trends in
microbiology 25.2 (2017): 100-112.
-Clemente, Jose C., et al. "The impact of the gut microbiota on human health: an integrative
view." Cell 148.6 (2012): 1258-1270.
-Hostrup, Morten, and Jens Bangsbo. "Limitations in intense exercise performance of athletes–effect of
speed endurance training on ion handling and fatigue development." The Journal of physiology 595.9
-Maukonen, Johanna, and Maria Saarela. "Human gut microbiota: does diet matter?." Proceedings of the
Nutrition Society 74.1 (2015): 23-36.
-Ríos-Covián, David, et al. "Intestinal short chain fatty acids and their link with diet and human
health." Frontiers in microbiology 7 (2016): 185.
14. References :
-O'Connor, Eibhlís M., Eileen A. O'Herlihy, and Paul W. O'Toole. "Gut microbiota in older subjects: variation,
health consequences and dietary intervention prospects." Proceedings of the Nutrition Society 73.4 (2014):
-Patterson, Elaine, et al. "Gut microbiota, the pharmabiotics they produce and host health." Proceedings of
the Nutrition Society 73.4 (2014): 477-489.
-Flint, Harry J., et al. "Links between diet, gut microbiota composition and gut metabolism." Proceedings of
the Nutrition Society 74.1 (2015): 13-22.