Persistent diarrhoea, defined as a diarrhoeal episode that starts acutely but then lasts for 14 days or more, is an important cause of morbidity and mortality in children under five years old in low- and middle-income countries. Although most of the pathogens that cause acute diarrhoea have also been associated with persistent diarrhoea, its exact cause and the pathogenic mechanisms are not well understood, making the management and treatment quite problematic. Risk factors for persistent diarrhoea include frequent acute diarrhoeal episodes, resulting in nutritional compromise, lack of breastfeeding and immune deficiencies.
Probiotics such as Bifidobacterium, Lactobacillus and Streptococcus, have been shown to be of benefit in acute infectious diarrhoea and in inflammatory bowel diseases through various mechanisms of action, and their properties may be beneficial in persistent diarrhoea as well. This review included randomized controlled trials of specific probiotics in children with persistent diarrhoea. Trials which used yogurt or other non-identified fermented foods were excluded. The authors identified four trials for inclusion, with a total of 464 participants. All trials were conducted in children up to six years of age, in hospitals in middle-income countries. There were notable differences in probiotics tested, treatment regimens, and outcomes measured.
Two studies with a total of 324 participants, showed that probiotics shorten the duration of diarrhoea and reduce the stool frequency on day 5. One study (235 children) suggested that probiotics reduce the length of hospital stay, and three out of four trials reported that no adverse events occurred. The authors conclude that despite these promising results there is insufficient evidence to recommend the use of probiotics for persistent diarrhoea, stressing the need for methodologically well-designed trials, with standardized definitions for persistent diarrhoea and the resolution of the illness, using specific probiotic strains.
Bernaola Aponte, G.; Bada Mancilla, C.A.; Carreazo Pariasca, N.Y.; Rojas Galarza, R.A. Probiotics for treating persistent diarrhoea in children. Cochrane Database of Systematic Reviews (2010) (Issue 11) Art. No.: CD007401. [DOI: 10.1002/14651858.CD007401.pub2]