In the Spring/Summer 2000 issue of the Newsletter, a short article stated that fenugreek tea may cause an odor in the urine similar to maple syrup. We receive many calls from persons who smell maple syrup in their own urine or on their child and wonder if they could have some form of MSUD even though they are not sick. Recently a woman, 39, who had raised a family, was diagnosed with intermittent MSUD. However, she had been very sick several times prior to the diagnosis. Are there many more undiagnosed cases?

After reading the article on the fenugreek tea odor, Dr. Neil Buist responded with a letter to me providing some additional information. I certainly appreciate his response, which follows.

The most common "MSUD" question that I usually get is about "healthy" children who smell of maple syrup (MS) as mentioned in the Spring/Summer issue. Almost all of these children are developmentally normal. Clearly, fenugreek is not the cause in most of these children, and indeed, it is not common to smell MS in children or adults who eat lots of fenugreek in curries.

I think that the smell (which derives from some unknown compounds) comes from what older clinicians used to call the "second liver" - the bowel. Gut bacteria are responsible for making certain essential nutrients and there are many types of bugs, either aerobic or anaerobic, that live in the gut. Many are not even identified! Not everyone has the same collection of bacteria nor is the population constant all the time. It has been shown that the adult bowel contains about a half pound (220 g) of living bacteria; what a metabolic powerhouse!

Anyway, I think that the MS smell comes from some of the anaerobic bacteria in the gut, which explains, of course, why there are no changes in the plasma amino acids or the urine organic acids in these cases.

- Neil M. Buist, M.D.


The MSUD Family Support Group is currently funding several research projects and we are proactively looking for researchers interested in developing new treatments or finding a cure for MSUD. Significant funding is necessary if we are to accomplish this goal.
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