What is the evidence for the use of probiotics in functional disorders?

Targeted therapies for diarrhea-predominant irritable bowel syndrome

Irritable bowel syndrome (IBS) causes gastrointestinal symptoms such as abdominal pain, bloating, and bowel pattern abnormalities, which compromise patients’ daily functioning. Common therapies address one or two IBS symptoms, while others offer wider symptom control, presumably by targeting pathophysiologic mechanisms of IBS. The aim of this targeted literature review was to capture clinical trial reports of agents receiving the highest recommendation (Grade 1) for treatment of IBS from the 2009 American College of Gastroenterology IBS Task Force, with an emphasis on diarrhea-predominant IBS. Literature searches in PubMed captured articles detailing randomized placebo-controlled trials in IBS/diarrhea-predominant IBS for agents receiving Grade I (strong) 2009 American College of Gastroenterology IBS Task Force recommendations: tricyclic antidepressants, nonabsorbable antibiotics, and the 5-HT₃ receptor antagonist alosetron. Studies specific for constipation-predominant IBS were excluded. Tricyclic antidepressants appear to improve global IBS symptoms but have variable effects on abdominal pain and uncertain tolerability; effects on stool consistency, frequency, and urgency were not adequately assessed. Nonabsorbable antibiotics show positive effects on global symptoms, abdominal pain, bloating, and stool consistency but may be most efficacious in patients with altered intestinal microbiota. Alosetron improves global symptoms and abdominal pain and normalizes bowel irregularities, including stool frequency, consistency, and fecal urgency. Both the nonabsorbable antibiotic rifaximin and the 5-HT₃ receptor antagonist alosetron improve quality of life. Targeted therapies provide more complete relief of IBS symptoms than conventional agents. Familiarization with the quantity and quality of evidence of effectiveness can facilitate more individualized treatment plans for patients with this heterogeneous disorder.

Targeted therapies for diarrhea-predominant irritable bowel syndrome

Irritable bowel syndrome (IBS) causes gastrointestinal symptoms such as abdominal pain, bloating, and bowel pattern abnormalities, which compromise patients' daily functioning. Common therapies address one or two IBS symptoms, while others offer wider symptom control, presumably by targeting pathophysiologic mechanisms of IBS. The aim of this targeted literature review was to capture clinical trial reports of agents receiving the highest recommendation (Grade 1) for treatment of IBS from the 2009 American College of Gastroenterology IBS Task Force, with an emphasis on diarrhea-predominant IBS. Literature searches in PubMed captured articles detailing randomized placebo-controlled trials in IBS/diarrhea-predominant IBS for agents receiving Grade I (strong) 2009 American College of Gastroenterology IBS Task Force recommendations: tricyclic antidepressants, nonabsorbable antibiotics, and the 5-HT(3) receptor antagonist alosetron. Studies specific for constipation-predominant IBS were excluded. Tricyclic antidepressants appear to improve global IBS symptoms but have variable effects on abdominal pain and uncertain tolerability; effects on stool consistency, frequency, and urgency were not adequately assessed. Nonabsorbable antibiotics show positive effects on global symptoms, abdominal pain, bloating, and stool consistency but may be most efficacious in patients with altered intestinal microbiota. Alosetron improves global symptoms and abdominal pain and normalizes bowel irregularities, including stool frequency, consistency, and fecal urgency. Both the nonabsorbable antibiotic rifaximin and the 5-HT(3) receptor antagonist alosetron improve quality of life. Targeted therapies provide more complete relief of IBS symptoms than conventional agents. Familiarization with the quantity and quality of evidence of effectiveness can facilitate more individualized treatment plans for patients with this heterogeneous disorder.

Successful treatment of asymptomatic or clinically terminal bovine Mycobacterium avium subspecies paratuberculosis infection (Johne's disease) with the bacterium Dietzia used as a probiotic alone or in combination with dexamethasone: Adaption to chronic human diarrheal diseases

A naturally occurring gastrointestinal disease, primarily of ruminants (Johne disease), is a chronic debilitating disease that is caused by Mycobacterium avium subspecies paratuberculosis (MAP). MAP infection occurs primarily in utero and in newborns. Outside our Dietzia probiotic treatment, there are no preventive/curative therapies for bovine paratuberculosis. Interestingly, MAP is at the center of controversy as to its role in (cause of) Crohn disease (CD) and more recently, its role in diabetes, ulcerative colitis, and irritable bowel syndrome (IBS); the latter two, like CD, are considered to be a result of chronic intestinal inflammation. Treatments, both conventional and biologic agents, which induce and maintain remission are directed at curtailing processes that are an intricate part of inflammation. Most possess side effects of varying severity, lose therapeutic value, and more importantly, none routinely result in prevention and/or cures. Based on (a) similarities of Johne disease and Crohn disease, (b) a report that Dietzia inhibited growth of MAP under specific culture conditions, and (c) findings that Dietzia when used as a probiotic, (i) was therapeutic for adult bovine paratuberculosis, and (ii) prevented development of disease in MAP-infected calves, the goal of the present investigations was to design protocols that have applicability for IBD patients. Dietzia was found safe for cattle of all ages and for normal and immunodeficient mice. The results strongly warrant clinical evaluation as a probiotic, in combination with/without dexamethasone.

Effects of probiotic Lactobacillus paracasei-enriched artichokes on constipated patients: a pilot study

GOALS

To determine whether the consumption of artichokes enriched with a probiotic Lactobacillus paracasei strain affects fecal microbiota composition, fecal enzyme activity, and short-chain fatty acids production and symptom profile in patients suffering from constipation.

BACKGROUND

Constipation is a common gastrointestinal disorder often related to the food diet. The beneficial effects of probiotics and prebiotics on human health are under investigation. Moreover, recent studies assessed the suitability of some vegetables, particularly olives and artichokes, to vehicle probiotic strains into the gastrointestinal tract.

STUDY

For 15 days, 8 volunteers (3M/5F age 40+/-14 y) integrated their normal diet with artichokes (180 gr) enriched with 20 billions of L. paracasei LMGP22043. Faecal samples were subjected to microbiologic and biochemical analyses. Besides, investigations on symptom profile of the volunteers and stool consistency were carried out by using a validated questionnaire (Gastrointestinal Symptom Rating Scale) and the Bristol stool form chart.

RESULTS

The gut of all volunteers resulted to be colonized by the probiotic strain after 15 days feeding. No significant differences in the microbiological counts throughout the experimental period were registered, whereas a significant increase of butyric and valeric acids with a concomitant decrease of lactic acid was registered. At the same time, the fecal beta-glucuronidase activity was significantly reduced. Finally, the analysis of symptom profile indicated a marked reduction in abdominal distension and feeling of incomplete evacuation.

CONCLUSIONS

These preliminary data suggest that novel approaches for treating constipation can come through ingestion of probiotic vegetable products that, acting as symbiotics, can ameliorate this common disorder.

From structure to function: the ecology of host-associated microbial communities

In the past several years, we have witnessed an increased interest in understanding the structure and function of the indigenous microbiota that inhabits the human body. It is hoped that this will yield novel insight into the role of these complex microbial communities in human health and disease. What is less appreciated is that this recent activity owes a great deal to the pioneering efforts of microbial ecologists who have been studying communities in non-host-associated environments. Interactions between environmental microbiologists and human microbiota researchers have already contributed to advances in our understanding of the human microbiome. We review the work that has led to these recent advances and illustrate some of the possible future directions for continued collaboration between these groups of researchers. We discuss how the application of ecological theory to the human-associated microbiota can lead us past descriptions of community structure and toward an understanding of the functions of the human microbiota. Such an approach may lead to a shift in the prevention and treatment of human diseases that involves conservation or restoration of the normal community structure and function of the host-associated microbiota.

The probiotic Bifidobacterium infantis 35624 displays visceral antinociceptive effects in the rat

BACKGROUND

Irritable bowel syndrome (IBS) is characterized by recurrent abdominal pain and altering bowel habit with a high percentage of patients displaying comorbid anxiety. Growing clinical and preclinical evidence suggests that probiotic agents may restore the altered brain-gut communication in IBS. In this study, we evaluated the efficacy of repeated treatment with three different probiotics in reducing visceral pain in visceral normosensitive (Sprague-Dawley [SD]) and visceral hypersensitive (Wistar-Kyoto [WKY]) rat strains.

METHODS

Following 14 days oral gavage of Lactobacillus salivarius UCC118, Bifidobacterium infantis 35624, or Bifidobacterium breve UCC2003 both SD and WKY rats were exposed to a novel stress, the open field arena and their behavior was recorded. Subsequently, the effects of probiotics on visceral nociceptive responses were analyzed by recording pain behaviors during colorectal distension (CRD).

KEY RESULTS

It was found that there was a difference in the open field behavior between strains but none of the probiotic treatment altered behavior within each strain. Interestingly, the probiotic B. infantis 35624 but not others tested significantly reduced CRD-induced visceral pain behaviors in both rat strains. It significantly increased the threshold pressure of the first pain behavior and also reduced the total number pain behaviors during CRD.

CONCLUSIONS & INFERENCES

These data confirm that probiotics such as B. infantis 35624 are effective in reducing visceral pain and may be effective in treating certain symptoms of IBS.

Colonic treatments and targets: issues and opportunities

The colon provides a plethora of therapeutic opportunities. There are multiple disease targets, drug molecules, and colon-specific delivery systems to be explored. Clinical studies highlight the potential for systemic delivery via the colon, and the emerging data on the levels of cell membrane transporters and metabolic enzymes along the gut could prove advantageous for this. Often efflux transporters and metabolic enzyme levels are lower in the colon, suggesting a potential for improved bioavailability of drug substrates at this site. The locoregional distribution of multiple metabolic enzymes (including cytochromes), efflux transporters (including P-glycoprotein and breast cancer resistance proteins), and influx transporters (including the solute carrier family) along the intestine is summarized. Local delivery to the colonic mucosa remains a valuable therapeutic option. New therapies that target inflammatory mediators could improve the treatment of inflammatory bowel disease, and old and new anticancer molecules could, when delivered topically, prove to be beneficial adjuncts to the current systemic or surgical treatments. New issues such as pharmacogenomics, chronotherapeutics, and the delivery of prebiotics and probiotics are also discussed in this review. Targeting drugs to the colon utilizes various strategies, each with their advantages and flaws. The most promising systems are considered in the light of the physiological data which influence their in vivo behavior.