Repeated antibiotics alter beneficial gut germs

[Guest guest]

Here is a report that came out a few days ago. (msn.com)

I know my Mom was ill when giving birth to me. She was in the hospital for

several months. And I'll bet was giving a ton of antibiotics.

I now take yogurt most every day.

Repeated antibiotics alter beneficial gut germs

Levels plummeted in volunteers in small study, researchers found

WASHINGTON — An antibiotic can temporarily upset your stomach, but now it turns

out that repeatedly taking them might have lingering ill effects — by triggering

changes in all those good germs that live in your gut.

Nobody yet knows if that leads to later health problems. But the finding is the

latest in a flurry of research raising questions about how the customized

bacterial zoo that thrives in our intestines forms — and whether the wrong type

or amount plays a role in ailments from obesity to inflammatory bowel disease to

asthma.

Don't be grossed out: This is a story in part about, well, poop. Three healthy

adults collected weeks of stool samples so that scientists could count exactly

how two separate rounds of a fairly mild antibiotic caused a surprising

population shift in their microbial netherworld — as some original families of

germs plummeted and other types moved in to fill the gap.

It's also a story of how we coexist with trillions of bacteria, fungi and other

microbes in the skin, the nose, the digestive tract, what scientists call the

human microbiome. Many are beneficial, even indispensable, especially the gut

bacteria that play an underappreciated role in overall health.

" Gut communities are fundamentally important in the development of our immune

system, " explains Dr. Relman of Stanford University, who led the

antibiotic study published Monday in Proceedings of the National Academy of

Sciences. " Let's not take them for granted. "

Next, Relman plans to track if antibiotics during the first or two year of life,

when youngsters form what will become their unique set of gut bacteria, seem to

predispose children to later immune-related diseases.

Antibiotics already should be used cautiously because they can spur

infection-causing bacteria to become drug-resistant. The new research raises

different questions about effects on beneficial bacteria — and if abnormalities

in the microbiome really are linked to health problems, how those changes might

begin.

We should start paying attention to this, " says Dr. Blaser, a microbiome

specialist at New York University Langone Medical Center, who wasn't involved

with Relman's work but also is planning to study the issue in children. " The

main point is that antibiotic use is not free in a biological sense. "

Everyone is born with an essentially sterile digestive tract, but within days

the gut is overrun with bacteria from mom and dad, the environment, first foods.

Ultimately, a healthy person's intestinal tract teems with hundreds of species

of microbes, the body's biggest concentration, with many involved in such things

as digestion and immune reaction.

In the not-so-healthy, scientists have discovered that overweight people harbor

different types and amounts of gut bacteria than lean people, and that losing

weight can change that bacterial makeup. They've also found links to other

digestive diseases, precancerous colon polyps — and even are pursuing a theory

that early use of antibiotics disrupts the developing microbiome in ways that

spur autoimmune disorders like asthma or allergies.

Antibiotics aren't choosey and can kill off good germs as well as bad ones. But

Relman and fellow research scientist Les Dethlesfsen wondered how hardy gut

bacteria are, how well they bounce back. So they recruited healthy volunteers

who hadn't used antibiotics in at least the past year to take two five-day

courses of the antibiotic Cipro, six months apart.

The volunteers reported no diarrhea or upset stomach, yet their fecal samples

showed a lot going on beneath the surface. Bacterial diversity plummeted as a

third to half of the volunteers' original germ species were nearly wiped out,

although some other species moved in. Yet about a week after stopping the drug,

two of the three volunteers had their bacterial levels largely return to normal.

The third still had altered gut bacteria six months later.

The surprise: Another die-off and shift happened with the second round of Cipro,

but this time no one's gut bacteria had returned to the pre-antibiotic state by

the time the study ended two months later.