Yakult probiotic yoghurt effective for small intestinal bacterial overgrowth

A small scale study has found that the probiotic yoghurt drink Yakult® effectively treats small intestinal bacterial overgrowth (SIBO) and reduces symptoms associated with irritable bowel syndrome (IBS).

Small intestinal bacterial overgrowth (SIBO) is a condition in which there is an increase in the numbers of unhelpful types of bacteria in the small intestine. The bacteria are often present in large numbers higher up in the small intestine than is normal. SIBO causes increased fermentation of sugars consumed in the diet and can cause symptoms such as abdominal bloating and flatulence.

SIBO has been shown to be unusually common in irritable bowel syndrome (IBS) and is thought to contribute to symptoms in some patients. Previous research has found antibiotics and low carbohydrate diets are somewhat effective.

Researchers at Monash University, Box Hill Hospital, Australia have now conducted a small study to determine if Yakult® probiotic yoghurt might be useful in the treatment of SIBO in IBS patients.

Yakult® is a yoghurt drink containing the probiotic bacteria Lactobacillus casei strain Shirota and is popular in many countries including Australia, the United Kingdom and the Republic of Ireland.

The researchers led by Peter Gibson recruited 18 IBS patients who met the Rome Ⅱ diagnostic criteria and who showed an early rise in breath hydrogen after consuming the sugar lactulose, an indicator of the presence of SIBO. The participants consumed 65 ml of Yakult® daily for 6 weeks with the breath hydrogen test being repeated at the end of the period and symptoms recorded daily using questionnaires.

The results of the study reported in the World Journal of Gastroenterology show that in 9 of 14 patients (64%) completing the study there was a decrease in the severity of the early rise in breath hydrogen and that this was associated with an improvement in symptoms.

The researchers conclude that the results indicate that Yakult® alters fermentation patterns suggesting a reduction in SIBO. They say however that further research is required to confirm the findings and that this should be in the form of controlled, randomised trials.