The intestinal equilibrium is significantly affected in cases of infectious diarrhea. Studying the microbial ecosystem over the course of the infection has resulted in notable progress in the treatment of this disorder.
Infectious diarrhea includes the majority of gastroenteritis, acute diarrheas (lasting less than 2 weeks), and traveler’s diarrhea. Infectious etiologies (viral, bacterial, parasitic) are predominant in this type of diarrhea. It’s a major public health problem in developing countries, in which 760,000 children die from it every year1. Children are the most affected by this disease in developed countries as well. However, when well treated, gastroenteritis (most often caused by rotavirus or adenovirus) almost always progress favorably.
A shaken equilibrium
Although sensitivity to infectious diarrhea seems to depend on the individual’s microbial profile2, the appearance of such diarrhea in turn disrupts the composition of the intestinal microbiota. Studies have shown that, whether the infectious diarrhea is of bacterial or viral origin, bacterial diversity falls for several weeks, with a particularly strong decrease in the proportion of bacteria from the Bacteroidetes and Firmicutes families3,4.
Potential long-term consequences
The microbiota is resilient, which allows it to rebalance itself and almost return to its initial state within several weeks following diarrhea5. Nevertheless, studies suggest that changes that persist long-term can have harmful consequences for health, particularly by stimulating the development of irritable bowel syndrome6.
The primary treatment is to counter dehydration. In addition to rehydration, studies suggest that taking probiotics like Saccharomyces boulardii may shorten the duration of infectious gastroenteritis by accelerating the restoration of the microbial equilibrium7,8.
1- Maladies diarrhéiques. In : OMS [en ligne]. Avril 2013. [consulté le 30/12/2016]. Disponible à l'adresse : http://www.who.int/mediacentre/factsheets/fs330/fr/
2- Lindsay B,et al. Microbiota that affect risk for shigellosis in children in low-income countries. Emerg Infect Dis 2015 ; 21 : 242-50. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4313639/pdf/14-0795.pdf
3- Monira S et al.. 2013. Metagenomic profile of gut microbiota in children during cholera and recovery. Gut Pathog5:1. doi:.10.1186/1757-4749-5-1 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3574833/pdf/1757-4749-5-1.pdf
4- Ma C, et al. Molecular characterization of fecal microbiota in patients with viral diarrhea. Curr Microbiol 2011 ; 63 : 259-66. https://www.ncbi.nlm.nih.gov/pubmed/?term=Ma+C%2C+Wu+X%2C+Nawaz+M%2C+et+al.+Molecular+characterization+of+fecal+microbiota+in+patients+with+viral+diarrhea.+Curr+Microbiol+2011+%3B+63+%3A+259-66.
5- Balamurugan R et al.. Molecular studies of fecal anaerobic commensal bacteria in acute diarrhea in children. J Pediatr Gastroenterol Nutr 2008 ; 46 : 514-9. https://www.ncbi.nlm.nih.gov/pubmed/18493205
6- Beatty JK, Bhargava A, Buret AG. Post-infectious irritable bowel syndrome: mechanistic insights into chronic disturbances following enteric infection. World J Gastroenterol. 2014;20:3976–3985. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3983453/pdf/WJG-20-3976.pdf
7- Allen SJ et al. Probiotics for treating acute infectious diarrhea. Cochrane Database of Systematic Reviews 2010, Issue 11. Art. No.: CD003048. DOI: 10.1002/14651858.CD003048.pub3 http://www.cochrane.org/CD003048/INFECTN_probiotics-for-treating-acute-infectious-diarrhoea
8- Dinleyici EC et al.. Effectiveness and safety of Saccharomyces boulardii for acute infectious diarrhea. Expert Opin Biol Ther 2012 ; 12 : 395-410