DEAR DR. ROACH: With the current focus on gut health, I have been hearing a lot about probiotic supplements. Who should take them? Does the number of bacteria matter more than the types listed on the container? Does one take them daily, for a brief time period, or for extended time periods? — K.V.S.

ANSWER: Probiotics are healthy bacteria in the large intestines that aid in digestion and possibly other functions in the body. Scientists are just beginning to understand how the intestinal bacteria (called the microbiome) affect many areas of health.

There are a few indications for probiotics that are well-accepted. The most important are in people with gastrointestinal conditions, especially in people with inflammation from inflammatory bowel disease. Some infections, including Clostridium difficile, may be prevented and treated with probiotics. This is not the primary treatment (which usually is antibiotics against C-diff), but it may be a useful adjunctive treatment or in recurrent cases. Gastroenterologists prescribe several different types of probiotics for these conditions. The particular type of probiotic may depend on the underlying condition and symptoms.

There is very preliminary data that suggest probiotics may be helpful in young children to prevent allergies, but it’s not solid enough to recommend yet.

Probiotics are generally safe, but there have been a few cases of the probiotics entering the bloodstream in people with diseased immune systems. They are fairly expensive, however.

Having healthy gut bacteria may be of benefit in people with no specific problems. However, it is not necessary to take in bacteria to have a shift to healthier gut flora. A diet more based in plants, whole grains and nuts, with less dairy, meat and sweets (such as the Mediterranean diet) showed clear changes in the microbiome in a few days, compared with a typical Western diet. There are so many benefits to this type of diet, including reduction in heart disease risk, diabetes risk and obesity, that I recommend this diet or a similar one rather than taking probiotics for people who are interested in improving gut health.

DEAR DR. ROACH: Please explain tethered spinal cord syndrome. I’m 68 and presenting with urine and fecal incontinence and a heavy feeling in my legs after having spine surgery last year. What are my options? — K.H.

ANSWER: A tethered cord usually is a problem that’s found in children, where the spinal cord gets attached to a structure in the spine. It happens often in spina bifida or similar conditions. However, it occasionally happens after spinal surgery in adults. Symptoms include sensory problems, such as pain or numbness; weakness (a feeling of heaviness often is muscle weakness); and loss of control of bladder and bowel.

In a case series of adults with tethered cord, surgical release improved sensory symptoms in 80 percent of people, motor symptoms in 70 percent and urinary symptoms in 50 percent. I don’t know of any effective nonsurgical therapy. The published literature followed people for two years after surgery, but noted that the spine can re-tether itself even after successful surgical repair.

This is a rare condition and one where finding a neurosurgeon with experience in tethered cord syndrome would be of immense value.

Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu or request an order form of available health newsletters at 628 Virginia Dr., Orlando, FL 32803. Health newsletters may be ordered from www.rbmamall.com.