Capsules containing frozen faecal material may help clear up C. difficile infections, research suggests.
Twenty people were given the therapy, using material from volunteers, in an attempt to treat serious diarrhoea caused by Clostridium difficile bugs.
The work builds on previous studies showing that faecal transplants may help reset the balance of bacteria in the gut.
But researchers warned people should not be tempted to make "home brews".
C. difficile bacteria live harmlessly in many people's guts alongside hundreds of other species - all competing for space and food.
But some antibiotics can kill off C. difficile's competitors, allowing the bugs to multiply and produce masses of toxins. This can lead to serious diarrhoea and may be fatal.
Strong antibiotics help some people but others go on to develop chronic infections.
For the latest research, a team of scientists from America and Israel treated 20 people with chronic C. difficile infections using frozen faecal capsules.
Each patient was given 15 capsules on two consecutive days.
For 14 of the 20 people involved their symptoms completely disappeared, with no recurrences in the following two months.
After another course of treatment, only two patients had further worrying episodes of diarrhoea.
Researchers have carried out successful faecal transplants before, a therapy that generally involves administering fresh excrement through a tube or directly to the colon.
But, writing in the Journal of the American Medical Association, researchers argue that this is uncomfortable, impractical and can carry risks for patients.
Their capsules were made using faecal material from four carefully screened healthy volunteers.
Prof Elizabeth Hohmann at Harvard Medical School, who carried out this research, said: "The small investigation provides preliminary data supporting the safety and efficacy of this approach.
"More experience and larger studies are needed to determine the long-term safety and efficacy."
Dr Ilan Youngster from Boston Children's Hospital, who was also involved in the report, added: "The use of capsules simplifies the procedure immensely, potentially making it accessible to a greater population.
"But while we are striving to make this treatment more accessible to patients it is important to remind people of the potential dangers of attempting 'home brew' faecal microbiota transplant using faecal material from family members or friends.
"This procedure should only be performed under strict medical supervision with material from thoroughly screened donors."
Dr Trevor Lawley, from the Wellcome Trust Sanger Institute in the UK, said: "Antibiotic use can disturb the healthy intestinal ecosystem.
"The idea is you physically put the good bugs back.
"This is exciting because they have taken this therapy on to a capsule. Many scientists are now working to ensure we have the most effective mixture of microbes."