Scientist - News - 22-12-2008:
Promising new studies on probiotics and IBS
Beintema, Nienke
Two independent British studies, involving Bifidobacterium and Lactobacillus strains, have shown a clear relationship between the consumption of these probiotics and a decrease of symptoms associated with irritable bowel syndrome (IBS).
Both studies will be published in the January issue of Alimentary Pharmacology & Therapeutics. The first study, which was conducted at the University of Sheffield (UK), was a double-blind, randomised, placebo-controlled trial involving 52 patients clinically diagnosed with IBS. For eight weeks, half of these patients received a multi-strain probiotic known as LAB4, commercially available under the name ProVen, while the other half took placebo. The multi-strain preparation comprised two strains of Lactobacillus acidophilus, one of Bifidobacterium lactis, and one of B. bifidum.
Through a questionnaire, participants reported their IBS symptoms every two weeks during the trial, as well as two weeks afterwards. Patients who took LAB4 reported significant benefits within two weeks. After four weeks, the majority reported a reduction in the severity and duration of abdominal pain, a reduction of abdominal bloating, improved daily bowel movement, and an improved quality of life. However, as the researchers emphasise in their study, the symptoms returned after the patients stopped taking the probiotic.
Bloating
The second study was carried out at the University Hospital of South Manchester UK). This, too, was a randomised, double-blind, placebo-controlled study in which patients consumed the test product or a control product. In this case the trial was conducted for four weeks, and the test product was a fermented dairy product, commercially known as Activia, containing B. lactis.
To measure any effects, all patients kept symptom diaries, recording the occurence and severity of abdominal pain, flatulence and bloating. The study also focused on distension, which is observable increase in abdominal girth, while bloating is used to describe the sensation of abdominal swelling. The researchers measured distension using an electronic system, sewn into a band of elastic fabric, which the patients wore around their abdomen like a belt. The electronic circuit was connected to a small data logger that recorded the abdominal girth for 30 seconds each minute. Finally, the researchers measured the time needed for food to pass through the gastrointestinal tract (‘transit time’), using a combination of chemical breath analysis and a set of markers that were ingested by the patients and subsequently followed through X-ray.
Overall symptom severity improved significantly in the group that received the probiotic yoghurt. This group also experienced a significant reduction of 39% in maximal distension – with a maximum effect of up to 78% – and a notable, though not significant, reduction in distension during the day. Importantly, the mean colonic transit time was accelerated by 12 hours, with a maximum of 22 hours. "Constipation, bloating and distension are common and distressing features of IBS," said lead author Peter Whorwell in a press release by Activia producer Danone, "with some sufferers being so bloated by the end of the day that they have to loosen clothing. Distension is associated with delayed gastrointestinal transit, so one of the mechanisms by which Activia may be helping this problem is by the acceleration of transit."
More information:
Sheffield publication in Alimentary Pharmacology & Therapeutics
ProVen’s information on the Sheffield trial
Manchester publication in Alimentary Pharmacology & Therapeutics
Danone press release
«BackPromising new studies on probiotics and IBS
Beintema, Nienke
Two independent British studies, involving Bifidobacterium and Lactobacillus strains, have shown a clear relationship between the consumption of these probiotics and a decrease of symptoms associated with irritable bowel syndrome (IBS).
Both studies will be published in the January issue of Alimentary Pharmacology & Therapeutics. The first study, which was conducted at the University of Sheffield (UK), was a double-blind, randomised, placebo-controlled trial involving 52 patients clinically diagnosed with IBS. For eight weeks, half of these patients received a multi-strain probiotic known as LAB4, commercially available under the name ProVen, while the other half took placebo. The multi-strain preparation comprised two strains of Lactobacillus acidophilus, one of Bifidobacterium lactis, and one of B. bifidum. Through a questionnaire, participants reported their IBS symptoms every two weeks during the trial, as well as two weeks afterwards. Patients who took LAB4 reported significant benefits within two weeks. After four weeks, the majority reported a reduction in the severity and duration of abdominal pain, a reduction of abdominal bloating, improved daily bowel movement, and an improved quality of life. However, as the researchers emphasise in their study, the symptoms returned after the patients stopped taking the probiotic.
Bloating
The second study was carried out at the University Hospital of South Manchester UK). This, too, was a randomised, double-blind, placebo-controlled study in which patients consumed the test product or a control product. In this case the trial was conducted for four weeks, and the test product was a fermented dairy product, commercially known as Activia, containing B. lactis.
To measure any effects, all patients kept symptom diaries, recording the occurence and severity of abdominal pain, flatulence and bloating. The study also focused on distension, which is observable increase in abdominal girth, while bloating is used to describe the sensation of abdominal swelling. The researchers measured distension using an electronic system, sewn into a band of elastic fabric, which the patients wore around their abdomen like a belt. The electronic circuit was connected to a small data logger that recorded the abdominal girth for 30 seconds each minute. Finally, the researchers measured the time needed for food to pass through the gastrointestinal tract (‘transit time’), using a combination of chemical breath analysis and a set of markers that were ingested by the patients and subsequently followed through X-ray.
Overall symptom severity improved significantly in the group that received the probiotic yoghurt. This group also experienced a significant reduction of 39% in maximal distension – with a maximum effect of up to 78% – and a notable, though not significant, reduction in distension during the day. Importantly, the mean colonic transit time was accelerated by 12 hours, with a maximum of 22 hours. "Constipation, bloating and distension are common and distressing features of IBS," said lead author Peter Whorwell in a press release by Activia producer Danone, "with some sufferers being so bloated by the end of the day that they have to loosen clothing. Distension is associated with delayed gastrointestinal transit, so one of the mechanisms by which Activia may be helping this problem is by the acceleration of transit."
More information:
Sheffield publication in Alimentary Pharmacology & Therapeutics
ProVen’s information on the Sheffield trial
Manchester publication in Alimentary Pharmacology & Therapeutics
Danone press release