Question

doi.org/10.1016/j.jmoldx.2019.01.C. Irritable bowel syndrome (IBS) is a functional gastrointestinal (GI) tract disorder affecting up to 20% of the world's popu- lation. IBS symptoms include bloating, altered bowel habits, and abdominal pain, with pain being the most debili- tating. The etiologies of IBS are multifactorial,8 and increasing evidence supports the involvement of gut microbes in IBS onset and symptoms. (HCs), IBS gut microbial communities (child or adult) of display greater heterogeneity and temporal instability and shifts in the relative abundances of members of the phyla Bacteroidetes, Proteobacteria (specifically, Gammaproteo- bacteria), and Firmicutes. In other reports, adults with IBS have been found to have altered fecal concentrations of me- 9-13 Relative to healthy controls tabolites that may be produced or modified by microbes including short-chain fatty acids, bile acids, and amino acid degradation products.5-17 Despite the growing number of IBS microbiome-based studies, little consensus exists with respect to IBS-associated alterations in microbial community structure, function, associated metabolites. This lack of consensus may be attrib- uted to varying molecular profiling methods, the limited reso- lution (ie, family or genus level) often associated with partial 16S rRNA gene data, varying definitions of IBS, subtypes evaluated, and/or other physiological factors. In addition, most past studies have relied diagnosis of IBS. However, in both children and adults, recall is unreliable and poorly correlated with prospective IBS symptom diary capture.819 Given this, recent expert guidance mends the use of prospective 2-week symptom diaries for clinical studies of IBS,20 but prospective diary-based guidance has yet to be implemented in many IBS microbiome studies. Our previous prospective diary-based characterization of or subject symptom recall to confirm on recom- I a la

can you please help me understand this passage and what they did in there experiment please ...I need I short explanation

Answer 1

In the above passage, the authors are studying the alteration in the gut microbiome of patients suffering from Inflammatory bowel disease (IBS). This was evident from the altered concentrations of metabolites produced by gut bacteria that includes: bile salts, degradation products of amino acids, short chain fatty acids, in feces of IBS patients. Here they want to correlate microbial ecology of IBS with the symptom severity and subtype and want to use they key microbial taxa as a tool to distinguish mild from severe IBS and healthy controls. For this they are integrate rigorous clinical phenotyping of IBS symptoms and pain severity with gut microbiome  and microbial metabolites, using genomics and metabolomics approach. Hence, they hypothesized that certain microbiome signatures and fecal metabolites can be associated with the frequency of abdominal pain and severity of IBS in children.

For achieving this, they recruited children suffering from IBS and age matched healthy controls and were rigorously classified as IBS cases by trained research coordinators, children suffering from other chronic conditions (such as diabetes, chronic vomiting) or on antibiotic or probiotic use were excluded from the study. The participants then maintained 2 week pain and stool diaries. The severity of pain was rated using a validated 10-point scale and correlated further with the microbiome and metabolite signatures.