Allergic diseases are increasing in prevalence worldwide. Chances are, you know someone with a condition like asthma, eczema, an allergy to specific foods or drugs, or even anaphylaxis (an acute hypersensitivity reaction that involves multiple body systems). But lately, groups of researchers around the world are looking at new solutions to treat—or even prevent—allergic diseases through the gut microbiota.
Several studies have linked the microbes in a developing child’s gut to different manifestations of allergic disease. The question is: could the gut microbiota in early life flag the children who are going to develop allergic disease later on, leaving open the possibility for intervening before that allergy manifests?
The studies focus on two main aspects: predictive value and actions that modify the gut microbiota
For asthma specifically, a picture is developing: children that lack four key microbial groups within their first 100 days are more likely to develop asthma by age three. Now, two recent studies have provided further insights about gut microbiota and allergic disease.
The first study looked at the broad spectrum of allergic diseases. The researchers selected two groups of Chinese children (from a larger study)—some who were healthy and some who were known to have an allergic disease: eczema, allergic rhinitis, asthma, or food allergy. The researchers found a high ratio of Klebsiella to Bifidobacteria at three months was correlated with an increased risk of allergic disease by three years of age.
Children who lack certain bacterial groups during their first 100 days of life are more likely to have asthma at a young age
Even as groups continue to investigate the predictive value of early-life gut microbiota in allergic conditions, other researchers are trialling interventions that modify the gut microbiota in an attempt to make a difference to allergic disease. Thus, in a second recent study (a randomized, controlled trial), one group of infants with suspected cow’s milk allergy was given a hypoallergenic infant formula with a prebiotic (fructo-oligosaccharides) and a probiotic (Bifidobacterium breve M-16V)—combined to make a ‘synbiotic’. Another group with the same suspected allergy was given formula minus the synbiotic. The researchers compared the fecal microbiota of both of these groups with that of healthy breastfed infants, and found the infants receiving the synbiotic formula had levels of fecal bacteria closer to what was seen in the healthy breastfed infants. Bifidobacteria were successfully increased in the ‘synbiotic’ group, but it was not certain what effect this may have had on disease course.
These two studies, while very different in their approaches, together reinforce the idea that the early-life gut microbiota is worth investigating for both the prevention and the treatment of allergic diseases.
Candy DCA, Van Ampting MTJ, Nijhuis MMO, et al. A synbiotic-containing amino-acid-based formula improves gut microbiota in non-IgE-mediated allergic infants. Pediatric Research. 2017. doi:10.1038/pr.2017.270
Low JSY, Soh S-E, Lee YK, et al. Ratio of Klebsiella/Bifidobacterium in early life correlates with later development of paediatric allergy. Beneficial Microbes. 2017. 8(5): 681-695.