Sparse Microbes Key To Health, ‘Bacteria Effect’ Far More Complicated Then Previously Believed

Modern medicine might have created a monster when doctors began administering antibiotics long before anyone had the slightest comprehension of the complicated connection between gut microbes and health. Now, antibiotics are everywhere. They are in medicine and food, and even in our water and soil. By now, it’s common knowledge that antibiotics have been abused and that our society has begun to enter a post-antibiotic era. Only recently, though, have researchers begun to grasp the legacy that our dependence on bacteria-killing substances will leave. The Inquisitr previously reported that healthy microbes within the gut are an endangered species, but if we change our ways, could we bring healthy microbiota back, or will our species simply have to evolve to find a new homeostasis in the bacterial environment that lives within us?

The FDA approved the use of antibiotics as growth promoters in healthy livestock in the early 1950s, according to Slate Magazine. By the 1960s, researchers began noticing a rise in antibiotic-resistant infections. It shouldn’t have been surprising. Antibiotic resistance was foreseen not long after they were first implemented in medicine. The New York Times called our victory over microbes through antibiotics and sanitizing in the 20th century “the peril of the 21st.”

H. pylori was once considered a bad bacteria, because it caused ulcers. Doctors tried to eliminate it with antibiotics. Given that bacteria is transferred from parent to child by being born, breastfeeding, and physical closeness, only six percent of American children born after 1995 have this microbe in their guts. Once considered a near success, it turns out H. pylori eradication efforts damaged the American microbiota. Scientists, only after doctors had already waged war on the bacteria, learned that the microbe might also be healthy in proper numbers. Losing the microbe is believed to be linked to a rise in asthma, allergies, acid reflux, and celiac disease.

Mountains of evidence now exist proving beyond doubt that that the trillions of microbes in our guts play a significant role in our health. Moving deeper into this area of biology, though, they are beginning to realize that the nuances among the gut flora are also crucial to good health. Some species of microbes have a powerful effect even in sparse numbers, according researchers from the University of Oregon in Eugene. Their research was published in Cell Host & Microbe.

In the study, “the genus Vibrio generated a rapid inflammatory response, while the genus Shewanella barely attracted any,” Medical News Today reported, but when the bacteria was mixed in a ratio of nine-tenths Vibrio and one-tenth Shewanella, the inflammatory response was controlled by the bacteria that was the fewest.

“Until now, we’ve only been able to capture proportional information, like you’d see displayed in a pie graph, of the makeup of various microbiota, in percentages of their abundance. Biologists in this field have typically assumed an equal contribution based on that makeup,” Dr. Annah S. Rolig, molecular biology researcher and first author of the publication, explained.

The team says that when studying the effects of bacteria in the gut, researchers will also need to start taking into account the “per-capita effect” of the microbes. Scientists had already realized that even the slightest shifts in the most abundant species will play a role in obesity, diabetes, Crohn’s disease and others, but the species found in fewer numbers have been relatively passed over as less important. The gut microbes present in less abundance, the team claims, secretes molecules that can dampen the size of the immune response. The molecules are still unidentified, though.

“Now we’ve shown that these minor members can have a major impact,” Dr. Rolig stated. “If we can identify these keystone species, and find that in a disease state one species may be missing, we might be able to go in with a specific probiotic to restore healthy functioning.”

Earlier this year, researcher from the Biomedical Informatics and Computational Biology program and the University of Minnesota published evidence that in the gut microbes caused by antibiotic use during infancy also causes numerous diseases later in life. Meanwhile, with altered gut microbes and antibiotic use, another study found that travelling Americans are probably responsible for spreading superbugs around the globe.

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