Can Bacteria Make You Skinny? Or Antibiotics Fatten You Up?



If only it were that simple, but physiology rarely is. But this does not mean you can’t use this info on probiotics and weight gain to your advantage.

Out of all the topics I’ve covered in the past 13 years and some 2500 blog posts, there are a few that stand out.  Vitamin D, exercise, diabetes prevention, chronic migraine relief. Probiotics, or those beneficial little buggers that should be present in your gut, is also way up on this list.

That is because the research on probiotics is everywhere across multiple specialties and any number of disease states. Many times I do not flag interesting journal articles on probiotics because I sound like such a darn broken record. So why am I doing it again? Certainly not boredom–I’ve got 20 other articles in my inbox for blog fodder. Maybe it’s because, at times, the evidence for a particular benefit becomes so overwhelming that it needs to be said again.

We are clearly at that point when it comes to probiotics and regulation of body weight.

The problem is that it is not a matter of having obese people add in some probiotics and “Viola!” They wake up skinny. The reality is that having the right blend of healthy bacteria in your gut seems to help set the tone for your body weight over a lifetime. This begins from birth. I recently had a patient with a 4 month old infant tell me that her pediatrician actually recommended probiotics, but that she should start after 6 months.

Well intentioned, but off base by 6 months. Passage through the womb begins the process and nursing continues the exposure of the newborn and infant to bacteria. Waiting for 6 months in a formula fed baby is just WAY too long to wait. This could potentially make the difference between a lifetime of being at an ideal weight versus this child fighting his weight for the rest of his life. Needless to say, I stressed how important it was not to wait 6 months.

As this particular article points out, the details on the process still are not ironed out.  Frankly, given the difference in everyone’s physiology and the hundreds of species of bacteria that are present in the gut, I don’t think we’ll ever get the specifics.

Besides this study, here are some previous blog articles looking at the relationship between probiotics and weight:

  1. Can antibiotics make you fat?
  2. Can the wrong gut bacteria make us fatter?

The take home message is twofold.  First, the use of antibiotics for non-life threatening situations needs to go away. Nothing will destroy the delicate balance of the bacteria in your gut faster than antibiotics.  Second, supplementation of probiotics intermittently is not a bad idea. This concept is particularly important for newborns, infants, toddlers and children.

My general recommendations are as follows:

  • Teens and Adults: 20 billion cfu / day taken one or two weeks per month.
  • Infants and toddlers: 5-10 billion cfu / day at least several days per week.
  • Preschoolers and elementary kids: 10-20 billion cfu several days per week.

While these recommendations vary greatly based on the individual situation, it is a good place to start.

James Bogash

For more than a decade, Dr. Bogash has stayed current with the medical literature as it relates to physiology, disease prevention and disease management. He uses his knowledge to educate patients, the community and cyberspace on the best way to avoid and / or manage chronic diseases using lifestyle and targeted supplementation.







Email:



Please note: I reserve the right to delete comments that are offensive or off-topic.

2 thoughts on “Can Bacteria Make You Skinny? Or Antibiotics Fatten You Up?

  1. Could you elaborate on brands or specific strains you prefer or recommend for your patients?

  2. Dr. Hommer,

    I generally use Biotic’s Biodoph 7 with 20 billion CFUs. If I need a much heavier-hitting probiotic, I will use VSL-3, which starts at 225 billion cfu.

    Dr. Bogash

Comments are closed.