P Robots are wildly popular. In the end, microbial cocktails are available without prescription and have shown that they help in the treatment of gastrointestinal diseases for some people.
But some scientists are afraid that probiotics are not as harmless as they seem – and can affect how other drugs work in the body.
The last caveat is in the form of a preliminary study published Tuesday, in which researchers found that patients with melanoma 70 percent less likely to respond to cancer immunotherapy if they also received probiotic supplements. The study group was small ̵
"We wanted to convey this to the avant-garde of people: that prescription-free probiotics are unnecessary, Dr Jennifer Warho, a leading research author and associate professor of the Department of Surgical Oncology at Dr. Anderson . "They may not help you and may even harm you."
Nowadays it is believed that a microbioma – or rather, trillions of different bacteria that flourish in each individual intestine – play a significant role in regulating the general health of humans. Demand for probiotic supplements is rapidly expanding, as consumers try to correct their perceived imbalances in their own sufferings; The world market, in 2013, was estimated at $ 36 billion . But since probiotics – like vitamins and other such supplements – are regulated only by the Food and Drug Administration, consumers can sprinkle these packaged bacterial spores with their standard therapeutic regimens.
And this could have serious consequences for their medical results.
"I strongly ask why the general public is taking probiotics when the medical evidence of this procedure is not really available," said Eran Elinav, an immunology researcher at the Weizmann Institute of Science in Israel.
Probiotic mixtures differ dramatically from tablets to pills. Companies are not even obliged to maintain the same combination of bacterial strains from one batch to another, which means that people who fall into their bodies may be very different. Some of these strains may interfere with the effectiveness of one drug, while others can strengthen it.
There are too many unknowns to make any given probiotic absolutely safe, says Dr. Peter Cohen, associate professor of medicine at Harvard Medical School, and a physician at the Cambridge Health Alliance who wrote about the problem of last year JAMA Internal Medicine
Probiotics work for some people and some conditions: They are useful for the treatment of colitis, for example, and other gastrointestinal diseases, said Dr. Rishi Sharma, gastroenterologist at Walnut Creek, California
Cancer patients often take probiotics to help relieve some of the side effects of treatment – in particular, diarrhea resulting from chemotherapy. Despite the fact that oncologists do not like offering their patients to take probiotics, many of the cancer's still doing: The MD Anderson study found that 42% of the patients were also taking probiotic supplements.
You see a study similar to this, suggesting that immunotherapy may not work so well – I would not have taken a probiotic, "said Sharma. – Your goal is to treat cancer.
Immunotherapy, as a rule, works in the quarter of patients with certain types of cancer, but it is still unclear why. A study by MD Anderson / Parker Institute was designed to test whether there was a correlation between diet, intestinal microbial and patient response to immunotherapy.
Forty-six patients with metastatic melanoma who began treatment at MD Anderson were asked to have a survey of what they ate and drank and what supplements they were taking. Before the start of therapy, researchers also took faecal samples from each patient – profiling the bacterial composition of the appropriate microbes. The study also found that higher fiber intake is correlated with lush microbials – and stronger reactions to immunotherapy.
The study was presented as an abstract by the American Cancer Research Association this week in Atlanta. It has not yet been published in the peer-reviewed journal.
"This study shows that the patient's response to immunotherapy is highly modulated by a microbiome," Elinav said.
Elinow said that the results were "perfectly consistent" with the findings of his own study: he published a couple of studies at Cell in 2018, discovering that probiotic supplements actually reduced the diversity of microbial members after they took the course of antibiotics. In fact, women who took probiotics took much longer than those who failed to fully recover.
Conclusions MD Anderson / Parker is far from complete. Vargo said that she and her team are expanding the group of patients being studied; They also collaborate with Seres Therapeutics, a biotechnology company in Cambridge, Mass., on whether combined probiotics can really improve immunotherapy. Nevertheless, not all researchers are convinced in the early conclusions.
The Parker Institute is currently conducting this test in collaboration with MD Anderson and Seres Therapeutics. This randomized, placebo-controlled clinical trial evaluates whether specially designed oral microbial pills with specific types of bacteria can positively affect the patient's response to testosterone inhibitors.
"I think this is a provocative conclusion," said Dr. Adil Dowd, a professor of medicine and director of clinical studies of melanoma at the University of California, San Francisco. "But I still think it's too early to really say that probiotics interfere with immunotherapy."
The trial was too small and a lot of variables could affect its outcome, he said. The microbiota varies greatly from person to person, and responses to immunotherapy may even vary depending on age, ethnicity, and gender.
Daud noticed that he has one patient with melanoma, which he treated with pemribrizamabom – immunotherapy anti-PD-L1. use probiotics. After the cessation of the drug, which proved to be effective, the tumor of the patient began to grow. When Dawood re-started pemrolizumab, the patient also decided to take a probiotic from Whole Foods; with the addition of the additive, the same drug had a long-term effect on the preservation of cancer.
"But this is isolated, n = 1 case – so I do not know how much weight it carries," said Dowd.
Daud tells his patients that instead of focusing on probiotics, they would be better off working on their diet – for example, increasing fiber consumption.
Cohen, a physician at the Cambridge Health Alliance, said that "he can not make heads or tails" of the latest study – he, in his opinion, is too small and vague.
"My two cents will be, this study reminds us that there is no doubt that probiotics affect the immune system," said Cohen. "This is the case, and we almost do not have the data to show that these living microorganisms really improve health."