In our continuing effort to improve the quality of life for people living with HIV, Community Research Initiative on AIDS this year conducted an open labeled pilot study to observe the health benefits and safety of SB-300 in people with HIV and chronic diarrhea.

Diarrhea is a frequent problem among patients infected with HIV. Over 50% and possibly up to 90% of all people with HIV will become afflicted with diarrhea at some point during their clinical course, requiring a physician visit or hospitalization for the syndrome. Diarrhea constitutes such a prevalent aspect of HIV that the Centers for Disease Control (CDC) has designated weight loss greater than 10% associated with more than 30 days of diarrhea in an HIV-positive individual as a criterion to the diagnosis of AIDS, even without an AIDS defining infection or malignancy.

SB-300 is a standardized herbal extract (dietary supplement) developed and sold by Shaman Botanicals. The company contributed the product for the study. It contains the compound SP-303 (proanthocyanidin oligomer) that has been isolated and purified from the bark of a South American Amazonian rainforest tree called Croton lechleri. The bark has a red latex that is taken orally by indigenous and mestizo peoples in numerous South American countries to treat diarrhea, dysentery, gastritis and stomach ulcers.

Although SP-303's precise cellular mechanism of action is not well understood, the agent has been found to block the secretion of fluid and chloride into the intestine. Pharmacokinetic studies in humans have demonstrated that there is no significant absorption of SP-303 into the bloodstream. Its anti-diarrheal action occurs entirely within the intestine.

Seven HIV+ participants were followed in CRIA's open labeled pilot study of SB-300, each of whom had had chronic diarrhea for two weeks prior to study enrollment. Chronic diarrhea was defined as three or more abnormal stools (i.e., soft or watery) per day. Diarrhea caused by an infection was ruled out in each case. Participants were required to discontinue any other anti-diarrheal agents 24 hours prior to enrollment. Each participant received SB-300 and was instructed to take two tablets (700 mg) every six hours for a two-week period. They were also asked to record in a diary the time and consistency of each stool for the duration of the study. Study visits were required at the end of each week.

The consistency of stools was broken into three categories for this study: watery (can be poured), soft (takes shape of container), and formed (retains shape).

The two weeks' experience on SB-300 were averaged for each participant and compared to the average daily estimates for the 10 days prior to enrollment. In addition to the two-week averages, we also examined averages for an 11-day period (day 4 - day 14) to determine whether there was an immediate response or if a few days' treatment were necessary.


Total StoolsWaterySoftFormed
Two-Week Average3.
11-Day Average3.

There appears to be a considerable decrease in the daily average number of stools, from 5.6 to 3.4, that is attributable to the treatment with SB-300. There is also a corresponding decrease in the average number of watery stools, accompanied by a decrease in the number of soft and an increase in the number of formed stools. The treatment appeared to be immediately effective since there were no significant differences between the two-week and 11-day averages.

The participants reported no side effects from SB-300 and generally acknowledged that the drug was beneficial to them. Prior to treatment, participants were largely confined to their homes due to the urgency of their diarrhea. Once on the SB-300, they spoke of a greater freedom to conduct normal lives as a result of their reduced problem of diarrhea.

While CRIA's pilot study into the efficacy and safety of SB-300 in the treatment of chronic diarrhea in HIV+ individuals shows some benefit, our results cannot be considered statistically significant given the small number of participants. To further research into this specific agent, CRIA has given its data to Dr. Johannes Koch at San Francisco General Hospital who is conducting a larger trial of SB-300. It is hoped that the results of our work and that of Dr. Koch will help improve the quality of life for the majority of PLWAs who will at some point develop chronic diarrhea.

The abstract of results from CRIA's Shaman SB-300 Diarrhea Study can be found on the Web at