Role of Probiotics in Diarrhea

Key messages:

• The use of antibiotics in early life changes the gut microbiota with possible long-term health implications.
• Dysbiosis in infectious diarrhea or antibioticassociated diarrhea can be prevented and treated with the use of probiotics.
• The strain that has the greatest effcacy in both disorders is Lacticaseibacillus (L)
rhamnosus GG (LGG) (previously known as Lactobacillus rhamnosus GG*) as confirmed by major clinical practice guidelines.

Infections and antibiotic use in early life:
Effects on the microbiome.

Infections are the most frequent reason for consultation in early life in both
emergency and primary care. Although most infections, usually respiratory and astrointestinal, are viral, many children are treated with antibiotics and their onsumption is three times higher than in adults. Antibiotics can change the resistance to colonization of the gut microbiota, resulting in diarrhea in up to 40% of cases.

Generally, all antibiotics can trigger it, although it is more frequent with those of wide spectrum. However, the main problem with the consumption of antibiotics is that they
can condition the development of our microbiota and their use during the first six months of life increases the risk of suffering from different diseases. Thus, their use has been associated with a greater risk of obesity, diabetes or autoimmune diseases, such as celiac disease.

How is the intestinal microbiota recovered?

The alteration of the gut microbiota or dysbiosis that is observed in many diseases can be corrected through the use of probiotics. The greatest evidence of their effectiveness has been described in the treatment of acute infectious diarrhea, especially in childhood, being more significant in diarrhea caused by rotavirus. The beneficial effects are greater the earlier probiotics are administered and their effcacy is characterized by
shortening the duration of the episode by approximately one day and decreasing the number of stools. A reduction in the rate of hospitalizations has also been observed,
a frequent cause in children under 3 years of age. When combined with antibiotics, they reduce the risk of antibiotic-associated diarrhea, although their administration should be done at the beginning of the treatment and not when the condition has developed.

Benefits of L. rhamnosus GG

But not all probiotics are the same and only some strains, mainly Lacticaseibacillus (L) rhamnosus GG (LGG) (previously known as Lactobacillus rhamnosus GG*) and Saccharomyces boulardii CNCM I-745 have proven to be effective in acute infectious diarrhea and antibioticassociated diarrhea. Evidence shows that, in general, LGG reduces both the duration of diarrhea and hospitalization in these patients, although the
effective dose has yet to be defined since beneficial effects have been mostly observed with ≥ 1010 CFU/day.1-3 The randomized clinical trials are included in the different clinical practice guidelines that demonstrate that LGG is the strain that has more scientific evidence as shown in the attached table based on the World Gastroenterology Organisation (WGO) guideline.4

This strain is also recommended in the latest ESPGHAN review, although the level of evidence is lower as more methodological rigour is applied.5 In short, we can conclude that LGG has beneficial effects on the infant by promoting a balanced or healthy microbiota.