Guest Post By Lara Briden

It’s not unusual for me to hear a story from a patient like this: “I don’t know what happened. I was doing really well with weight loss, but then suddenly I just ballooned.”

When I hear that, I ask: “Did you take antibiotics sometime in the last 3-4 months?” Very often, the answer is “Um… Oh right! Yes, I did.”

Weight gain from antibiotics is a clinical reality. The research is finally starting to catch up.

What Is The Research?

In 2012, British researchers reported that children exposed to antibiotics early in life are more likely to become overweight later in life. Professor Martin Blaser from New York University’s Langone Medical Center has also done some fascinating studies. First, he demonstrated that mice exposed to antibiotics gained twice as much weight as untreated mice on the same diet. Professor Blaser then looked at humans. He monitored 92 subjects after one course of antibiotics for H. pylori bacteria, and found that their weight increased significantly. He also detected a dramatic increase in blood levels of the ‘hunger hormone‘ ghrelin. Made by stomach cells (and normally suppressed by H. Pylori), ghrelin is a strong appetite stimulant and promoter of belly fat. In Professor Blaser’s study, ghrelin increased by 6 times, and stayed high for at least 18 months. The satiety hormone leptin was also affected.

The ghrelin effect is just one mechanism for the weight gain caused by antibiotics. Antibiotics damage intestinal bacteria, and that translates into metabolic changes that we are only just starting to understand. Intestinal bacteria determine how many calories you absorb. They manufacture nutrients and reduce inflammation. Intestinal bacteria have a direct influence on lipid metabolism and insulin sensitivity.

Antibiotics also damage mitochondria. That affects weight because mitochondria’s main job is to convert food into energy. If you have not yet heard of mitochondria, then get ready. You are going hear a lot more about them very soon. Mitochondria are major players in health. They are tiny organelles that exist in each and every cell. Mitochondria burn calories. They also boost communication between synapses in the brain, manufacture heme (the main protein in hemoglobin), and slow aging (just to name a few of the many, many things that they do for us).

How Many Courses Of Antibiotics Is Too Many?

I used to ask patients: “Do you take many antibiotics?”

I no longer ask that question, because the answer was invariably: ‘not many.’ By ‘not many,’ most people meant one course of antibiotics per year. One course per year is apparently now perceived as normal and standard. Eek!

One course of antibiotics per year is too many. A better figure would be one or two courses in a lifetime. Antibiotics are amazing, life saving drugs. I don’t like to imagine a world without them. But they are for life-threatening infections such as a kidney infection. They’re not for regular consumption.

I’m not asking you to say no to antibiotics if you really need them. The time to make the decision against antibiotics is not when you’re dealing with a full-blown chest or sinus infection. The time to make the decision is now, as prevention, before you get to that point. If you are prone to frequent infections, then you need an immune strategy like zinc, vitamin D and a dairy-free diet.

This is what I say to my patients: “I am prescribing an immune-boosting, antibiotic-avoiding strategy as part of your long-term weight loss plan.”

Probiotic Supplements Cannot Fix The Problem

Probiotics are not a solution.

I feel bad if natural medicine has somehow promoted the myth that [you can] ‘just take this probiotic after antibiotics’ and all will be well. All will not be well. Probiotics relieve symptoms, and they prevent infection with bad bacteria like Clostridium. But probiotic supplements do not recolonize your intestine.

There is growing evidence that antibiotics cause a permanent extinction of some species of intestinal bacteria. Probiotics cannot change that.

By Lara Briden

Lara is a natural health evangelist, hormone expert and author of Period Repair manual who first worked as an evolutionary biologist at the University of Calgary. She went on to graduate as a naturopathic doctor from the Canadian College of Naturopathic Medicine (CCNM) in Toronto. Her love of science and the natural world has informed the way she practices medicine. During her nearly twenty years of practice, thousands of patients have entrusted her with their hormone stories. She shares what she’s learned at larabriden.com.