When to Use Probiotics With Weight Loss Surgery

Probiotics are live microorganisms (bacteria and yeast) that have health benefits. Many probiotics help your body function properly, especially your digestive system. The body is full of bacteria, both good and bad. Bacteria that naturally reside in your intestines help your body digest food, produce vitamins (specifically vitamin K), and play a role in immunity. These “friendly” bacteria help your body maintain a healthy balance and keep bad bacteria from overwhelming your system and causing problems.

In addition to probiotics found naturally in your body, probiotics are also sold as additions to foods (like yogurt or kefir) and dietary supplements. The most common bacteria used in probiotic supplements are Lactobacillus and Bifidobacterium. Lactobacillus is the most common probiotic and can be found in yogurt and other fermented foods. Some strains of Lactobacillus can help with diarrhea and may help people suffering from lactose intolerance (the sugar found in milk). Bifidobacterium can also be found in dairy products and may help ease symptoms of Irritable Bowel Syndrome (IBS).

Researchers studying probiotics have found that these beneficial microorganisms may help prevent or treat a variety of conditions, including:

  • Digestive disorders (infectious diarrhea, Irritable Bowel Syndrome, lactose intolerance, Crohn’s disease, etc.)
  • Allergic disorders
  • Skin conditions (eczema)
  • Tooth decay and various other oral health problems
  • Infant colic
  • Liver disease (nonalcoholic steatohepatitis or NASH)
  • The common cold
  • Urinary tract and vaginal infections
  • Prevention of colon cancer

Probiotics and Weight Loss Surgery

After weight loss surgery, the balance between “good” and “bad” bacteria may become altered. This is due to disruption of your GI tract, as well as the use of antibiotics after surgery to help prevent infection. While antibiotics can help keep harmful bacteria at bay, they can also wipe out the good bacteria in your body. The number and type of intestinal bacteria is regulated by both intestinal motility and gastric acid secretion, which are both altered with the RNY Gastric Bypass. A bacterial overgrowth can lead to vitamin deficiencies, fat malabsorption, and in some cases malnutrition.

In a study from Stanford University School of Medicine, researchers found that those patients who took a probiotic after Gastric Bypass tended to lose more weight than those that did not take a probiotic supplement.

This study showed that at three months post-op, the probiotics group had a 47.6 percent weight loss, while the control group had a 38.5 percent weight loss. The group taking probiotics had a statistically significant reduction in bacterial overgrowth compared to the control group. This study also found that the group taking probiotics had a higher level of vitamin B12 than those in the control group (not taking a probiotic). This is significant because post-gastric bypass patients typically have low levels of vitamin B12. Probiotics may also decrease the incidence of “pouchitis”, a common intestinal inflammation after some bariatric surgeries.

Probiotic Supplements and Foods

The Food and Drug Administration (FDA) regulates probiotics as foods, not as medications. This means that the makers of probiotic supplements do not have to show they are safe or that they work.

In general, probiotic foods and supplements are thought to be safe for most people. Some people with immune system problems or other serious health conditions (critically ill people or those that have recently had surgery) should not take probiotics. In those that are generally healthy, side effects of probiotics are typically mild and consist of mild gastrointestinal symptoms (like gassiness).

Many foods also contain probiotics. These foods include:

  • Yogurt (with “live and active cultures”)
  • Sauerkraut (unpasteurized)
  • Miso soup
  • Some fermented soft cheeses (like Gouda)
  • Kefir (fermented milk drink)
  • Cottage cheese
  • Sourdough
  • Acidophilus milk and buttermilk
  • Tempeh

There are many over the counter (OTC) probiotics available. These include Align (B. infantis), Florastor (S. boulardii), Garden of Life probiotic (16 different strains), and Culturelle (Lactobacillus). Depending on the type of probiotic taken, one dose level for one strain is not necessarily the same effective dose as a different strain. Probiotics with at least 5 billion colony forming units (CFUs) per dose and contain at least seven strains of probiotics appear to be the most effective. Probiotics are most effective when taken with meals (unless the label states otherwise). Probiotics come in many forms, including pills, powders, liquids, capsules, and chewable tablets. For post-weight loss surgery patients, I would recommend a chewable probiotic to start, with the option of switching to a capsule when appropriate.

Always consult your health care provider before starting probiotics or any other dietary supplement.


Lauren Robinson is the Lead Dietitian and Manager at Bariatric Dietitian Services. She earned her BS in Nutritional Sciences with an emphasis in Exercise from Oklahoma State University and her MS in Nutrition from Texas Woman’s University. She has worked with over 5000 patients since beginning her career in bariatrics, and especially enjoys helping post-weight loss surgery patients get back on track!

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