Extragastrointestinal Symptoms ... During Breath Tests distinguish patients with functional gastrointestinal disorders, 2020, Wilder-Smith

[rvallee]

https://journals.lww.com/ctg/Fulltext/2020/08000/Extragastrointestinal_Symptoms_and_Sensory.12.aspx

Patients with functional gastrointestinal disorders (FGIDs) are classified based on their gastrointestinal (GI) symptoms, without considering their frequent extra-GI symptoms. This study defined subgroups of patients using both GI and extra-GI symptoms and examined underlying mechanisms with fructose and lactose breath tests.

Six symptom clusters were identified in 2,083 patients with FGID. Clusters were characterized mainly by GI fermentation-type (cluster 1), allergy-like (cluster 2), intense pain-accentuated GI symptoms (cluster 3), central nervous system (cluster 4), musculoskeletal (cluster 5), and generalized extra-GI (cluster 6) symptoms. In the 68% of patients with complete breath tests, the areas under the curve of GI and central nervous system symptoms after fructose and lactose ingestion differed across the clusters (P < 0.001). The clusters with extensive long-term extra-GI symptoms had greater symptoms after the sugars and were predominantly women, with family or childhood allergy histories. Importantly, the areas under the curves of hydrogen and methane breath concentrations were similar (P > 0.05) across all symptom clusters. Rome III criteria did not distinguish between the symptom clusters.

Patients with FGID fall into clusters defined extensively by extra-GI symptoms. Greater extra-GI symptoms are associated with evidence of generalized sensory hypersensitivity to sugar ingestion, unrelated to intestinal gas production. Possible underlying mechanisms include metabolites originating from the intestinal microbiota and somatization.

Prevalence estimates of the 18 long-term symptoms used for cluster analysis are reported in Table 1. Across all patients, the most prevalent GI symptoms were bloating (84%) and abdominal pain (70%), whereas the most frequent extra-GI symptoms were tiredness (67%) and concentration problems (35%); 55% of patients reported at least 1 allergy. The numbers of GI and extra-GI symptoms in individual patients were positively correlated (ρ = 0.35; P < 0.001).

Item response probabilities for all patients and the 6 clusters are reported in Table 1. Face validity was apparent for all clusters, with most marked distinction in the distributions of extra-GI symptoms. GI fermentation-type symptoms, such as bloating, pain, stool changes, and epigastric pain/heartburn, were present across all 6 clusters, but almost exclusively characterized cluster 1 (35% of patients). Cluster 2 (6%) was distinguished by additional allergy-like symptoms, cluster 3 (19%) by intense pain-accentuated abdominal symptoms, cluster 4 (17%) by CNS symptoms, cluster 5 (10%) by musculoskeletal symptoms, and cluster 6 (14%) by generalized multiorgan symptoms. The prevalence of allergies was highest in clusters 2 (75%) and 6 (79%) and lowest in clusters 1 (45%) and 4 (40%).

 

[rvallee]

It looks like treating multi-system diseases by siloing some symptoms into specialties who only look at a few features and otherwise limiting the multi-system part to "somatization", whatever that means, is not particularly smart.

Multi-system diseases needs their own specialty, capable of working across the various disciplines, without the woo and obsessive ideology of psychiatry and their ridiculous conversion disorder.

 

[Kitty]

As an aside, it seems ingestion of sugar is problematic across a fairly wide spectrum of ME patients. Not necessarily because it causes GI symptoms (though it may), but because it tends to aggravate all ME symptoms.

I've often wondered whether this is an important clue that should be investigated...or whether the explanation is so obvious to doctors that they don't even bother explaining it. I've seen lots of theories about candida overgrowth and so on, usually from patients, but not much actual research.