Researchers have discovered a promising solution to the growing threat of antibiotic-resistant bacterial infections in the gut. By isolating 18 beneficial bacterial strains from healthy individuals, they’ve found a way to curb the growth of dangerous Enterobacteriaceae bacteria and alleviate gut inflammation, offering a targeted and potentially more effective alternative to traditional treatments.
Fighting Antibiotic Resistance
For patients with chronic inflammatory diseases such as IBD, or those who have long-term courses of antibiotics, infections with antibiotic-resistant bacterial strains are an increasing area of concern.
The vast majority of these infections, caused primarily by Gram-negative Enterobacteriaceae bacteria such as E. coli or Klebsiella, are not responsive to current antibiotics. Though fecal microbiota transplants have proven beneficial, they can also be inconsistent in their composition and effectiveness.
With these shortcomings in mind, scientists at Keio University School of Medicine in Japan and the Broad Institute at MIT and Harvard set out to look for a more focused and potent solution — an approach that would use the complex community of microorganisms living in our guts and potentially fight these longtime pests.
Exploring the Secret 18 Star Strains
To do this, they obtained stool samples from five healthy donors and isolated around 40 bacterial strains from the samples that might be able to inhibit Enterobacteriaceae growth in mice infected with either E. coli or Klebsiella.
Among this collection of 41 strains, through testing it they could narrow the most effective microbes — around 18 strains that were found to good at suppressing pathogenic bacteria and reducing inflammation in the colon.
Nitrogen starvation results in conversion of gluconate to energy store Urhines, and beneficial strains rapidly out-competed Enterobacteriacea for this key nutrient, limiting the growth and colonization of these pathogenic bacteria. This resource competition may be an important component allowing these strains to invade and displace the gut-dwelling antibiotic-resistant Enterobacteriaceae.
In addition, the 18 strains did not inhibit other commensal bacteria even in inflamed gut microbiomes (Figure 1), indicating their potential beneficial effects with low side-effect profile.
Conclusion
That these 18 bacterial strains can robustly inhibit the development of antibiotic-resistant Enterobacteriaceae and resolve inflammation in the gut also reveals a novel perspective upon treatment strategy against such troublesome large family of infections. Through the study of the gut microbiome, investigators are working toward personalized microbial therapies which may represent a more precise and safer alternative to existing antibiotic treatments. This advance is a major step in fighting back against one of the greatest health challenges we face today: antibiotic resistance, which costs approximately 700,000 lives per year worldwide.
