In a new study, Danish and Ethiopian researchers linked chronic diarrhea to a specific type of gut bacteria. This discovery may pave the way for new treatments capable of saving lives.
Our intestines are home to bacteria. Bacteria train our immune systems to be resilient. These bacteria also produce some vitamins and convert the foods we consume into beneficial compounds. This imbalance in the gut microbiome can be linked to various diseases, including obesity, diabetes, and diarrhea.
Acute and chronic diarrhea is a widespread problem among children in developing countries, killing half a million children under the age of five every year. Acute diarrhea often goes away on its own and can usually be treated with antibiotics.
But its development into a chronic form can make children severely ill and immature, making treatment more difficult. The cause of chronic diarrhea remains unclear.
“Persistent diarrhea in adults can be very annoying, but it is rarely life-threatening,” explains Denis Sandris Nielsen, a professor at the Department of Food Science at the University of Copenhagen, according to Eurek Alert. “For children, however, it can have lifelong consequences.”
“While acute diarrhea has become more treatable over the past 50 years, little progress has been made in treating the chronic type, and that’s what piqued our interest.”
In a new study published in the journal Nature Communications on September 2, Nielsen and his Ethiopian colleague Getent Tesfu mapped the gut microbiome of more than 1,300 children under the age of five in Ethiopia. The main conclusion of the study was clear: children with chronic or persistent diarrhea had lower and significantly different bacterial diversity compared to healthy children.
“Our results show a clear link between the composition of gut bacteria and the duration of diarrhea,” explains Tesvo, a doctoral student who will defend his thesis on the topic later this November. “Children with chronic diarrhea are not only infected with a lot of harmful bacteria, but “They also suffer from fewer beneficial bacteria.”
A vicious cycle of diarrhea
Researchers used DNA sequencing to identify different beneficial and harmful bacteria in stool samples. The results indicate that children with chronic diarrhea have an excess number of harmful bacteria, while the presence of beneficial bacteria is significantly low.
The study also revealed that children suffering from chronic diarrhea lack bacteria that produce short-chain fatty acids, which are normally produced by beneficial bacteria and play an essential role in intestinal health.
Acute diarrhea is defined as diarrhea that lasts from one to six days, while chronic diarrhea lasts for a week or more. “The results suggest that chronic diarrhea develops if beneficial microbes producing short-chain fatty acids are lost, to the extent that children’s gut microbiota for unknown reasons fail to recover after antibiotic treatment for severe cases, for example,” Nielsen says.
The occurrence of persistent diarrhea appears to be driven by a loss of beneficial bacteria. We don’t yet know the exact cause, but we speculate that while antibiotics may be necessary to treat severe diarrhea, they also kill off beneficial gut bacteria. “As a result, children may get into a vicious cycle where chronic diarrhea takes over because they are not consuming the right foods to restore these beneficial bacteria.”
A popular food that may save children
New mapping of gut bacteria in children with chronic diarrhea provides a deeper understanding of the causes of the problem and facilitates the development of new, targeted therapies that can restore a healthy gut microbiome.
Tsevo suggests that the primary focus of treatment should be on designing an optimal diet to help restore the gut microbiome in affected children. Ideally, this diet should be familiar to local people, easily accessible and sustainable. Researchers have already thought of a food that would play this role.
“In Ethiopia, they have a superfood grain called teff, which is rich in nutrients and fiber. It clearly has the potential to act as a nutritional supplement that can help stop chronic diarrhea,” Nielsen says.