This is because, strains in most commercially produced probiotics were chosen for their easy growth – not because they are well-adapted to function in the human body. Therefore, they fail to colonise the gut and instead, simply pass through the body.
Despite that, the probiotic concept – that bacteria can beneficially adjust our immune systems to protect us from disease – is sound. Scientists are just trying to find the right strains to establish the groundwork concept.
One such team, led by Pinaki Pangrahi, a paediatrician at the University of Nebraska Medical Centre, has been overwhelmingly successful. It has identified a probiotic found in fermented vegetables, kimchi and other Asian kitchen staples, to counter sepsis.
Sepsis is the cause of death of nearly 600,000 babies worldwide each year. "All the sudden, the baby stops being active. It stops crying and breastfeeding. By the time the mother has a chance to bring the baby to the hospital, the baby dies," says Pangrahi.
A truly phenomenal result after nearly a decadeSince 2008, the team began identifying the best strain of bacteria to protect against sepsis. "We screened more than 280 strains in preliminary animal and human studies. So, it was a very methodical process,” explains Pangrahi.
Stool from healthy individuals were collected and screened for microbes. The team was specifically looking for ones that would both attach to human cells and prevent disease-causing bacteria from doing the same.
Eventually, the team landed on Lactobacillus plantarum as it attaches to gut cells. Adding sugar to nourish the probiotic whilst in the gut – it created a combination called a synbiotic.
The team fed half of 4,500 randomly selected new born babies in rural India with the synbiotic, while the other half were given a sugar placebo.
Babies who took this concoction showed a significantly lower risk of developing sepsis – only 5.4% of the babies developed sepsis compared to the 9% from the group given the placebo. That is a reduction of 40% and even with an error margin, the risk of getting an infection would still be between 25 and 50%.
The effect was twice as large as what the team expected; a truly phenomenal result, especially since the babies only took the probiotic for one week. Independent experts decided to stop the study because it would have been unethical to continue to deprive the other half of the babies, the probiotic mixture.
More than just preventing sepsisThe study also proved a reduction of the risk of infections by Gram-positives, by 82%; and Gram-negatives, by 75%. Additionally, it also reduced the risk of lung infections, such as pneumonia, by 34%.
"That was a big surprise, because we didn't think gut bacteria were going to work in a distant organ like the lung," remarks Panigrahi. This hints at an ability to provide body-wide protection.
The only significant side effect seen in the study was abdominal distension, which occurred in six infants; but there were more cases of this seen in the placebo group.
Best of all, the probiotic is inexpensive; it only costs USD1 to make a week's worth of probiotic. This treatment would also reduce the need for antibiotics, which would help slow antibiotic resistance.
“It’s a very important study,” says Marie-Claire Arrieta from the University of Calgary. “It not only shows an effective and low-cost way to prevent a horrible infant disease that kills millions worldwide – but, also provides important clues on how to improve strategies to change the infant-gut microbiome.”
“Probiotics can be much more powerful than drugs” – more testing requiredAccording to Dr Pascal Lavoie, a neonatologist at BC Children's Hospital in Vancouver, British Columbia, the probiotic can either change the environment in the gut, subsequently pushing the sepsis-causing bacteria out; or they can use up all the resources. They can also produce a compound that strengthens the wall of the intestine.
"It acts as a barrier to prevent the bad bacteria from going through the wall into the blood," Lavoie says. Additionally, "they can promote maturation of the immune system in a healthier way," he adds. "Probiotics can be much more powerful than drugs."
However, much like drugs, the probiotics need to be fully tested before they can be used widely. Panigrahi’s experiment only included healthy new-borns, of a good weight that were breastfed by their mothers and were therefore well positioned to fight off infections. Testing on babies with a high risk for sepsis – premature and underweight babies – is needed.
Researchers are also yet to learn why this works and what effect it may have on the microbiomes of the infants in the long run. MIMS
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