 [ Symptoms ] how can colon cancer be prevented [ Disease ] most helpful answer well first let me say no one should take more than the recommended dose of any medication or supplement there is usually a good reason why those limits were set just because supplements are often labeled as natural or healthy does not mean you can not experience serious side effects by taking too much of any given product that said i doubt taking a lot of probiotics would cause weight loss probiotics replenish the good flora of the intestinal tract which probably has no effect on the uptake of nutrients but theoretically can prevent diarrhea caused by taking antibiotics possibly help prevent urinary tract infections and have a beneficial effect on colon inflammation if your wife is experiencing unintended weight loss you are right to be concerned only an examination by a medical professional can help her figure out what is causing the weight loss i would suggest she make an appointment with her primary health care provider to discuss the issue best of luck to you both