Civilisation and the colon: constipation as the "disease of diseases"

Gut microbiota as a sensor of autoimmune response and treatment for rheumatoid arthritis

Rheumatoid arthritis (RA) is considered a multifactorial condition where interaction between the genetic and environmental factors lead to immune dysregulation causing autoreactivity. While among the various genetic factors, HLA-DR4 and DQ8, have been reported to be the strongest risk factors, the role of various environmental factors has been unclear. Though events initiating autoreactivity remain unknown, a mucosal origin of RA has gained attention based on the recent observations with the gut dysbiosis in patients. However, causality of gut dysbiosis has been difficult to prove in humans. Mouse models, especially mice expressing RA-susceptible and -resistant HLA class II genes have helped unravel the complex interactions between genetic factors and gut microbiome. This review describes the interactions between HLA genes and gut dysbiosis in sex-biased preclinical autoreactivity and discusses the potential use of endogenous commensals as indicators of treatment efficacy as well as therapeutic tool to suppress pro-inflammatory response in rheumatoid arthritis.

Chronic Constipation as a Risk Factor for Colorectal Cancer: Results From a Nationwide, Case-Control Study

BACKGROUND & AIMS

Prolonged colon transit times may increase the contact time between potential carcinogens in the stool and the colonic mucosa. Nonetheless, previous studies have yielded conflicting results connecting chronic constipation with the risk of colorectal cancer (CRC). We examined the association between chronic constipation and later CRC.

METHODS

In this nationwide case-control study, we identified 41,299 CRC cases by colorectal biopsy in Sweden between July 2007 and December 2016 and matched them to 203,181 age- and sex-matched controls from the general population. We compared odds of earlier chronic constipation (defined as ≥2 laxative prescriptions in the Prescribed Drug Register with ≥6 months between the first and last prescription) between CRC cases and controls using logistic regression. In separate analyses, we compared odds of earlier constipation between CRC cases and sibling comparators, but also examined earlier risk of having an inpatient/outpatient specialty diagnosis of chronic constipation before CRC.

RESULTS

Overall, 3943 patients with CRC met our criteria for chronic constipation before CRC. The crude proportion of chronic constipation in CRC patients was 9.5% compared with 8.8% in controls. After multivariable adjustment, there was a modest association between chronic constipation and later CRC (odds ratio [OR], 1.10; 95% CI, 1.06-1.14) that vanished using sibling comparators to control for residual confounding (OR, 1.04; 95% CI, 0.97-1.13). In a sensitivity analysis of 126,650 CRC patients diagnosed from 1989 to 2016, we found no association with earlier chronic constipation diagnosed in inpatient/outpatient specialty clinics (OR, 0.88; 95% CI, 0.75-1.04).

CONCLUSIONS

In a nationwide case-control study, chronic constipation was not associated with later CRC.

Autointoxication and historical precursors of the microbiome-gut-brain axis

This article focuses on autointoxication, a discredited medical theory from the late nineteenth century that provides important points of reflection for today's research on the role of microbes in the human gut for mental health. It considers how the theory of autointoxication, which came into great prominence amongst physicians and the general public worldwide, fell from grace by the middle of the twentieth century, and briefly asks why studies of the human microbiome are now back in vogue. It departs from earlier articles on the topic firstly by arguing that autointoxication theory was especially prevalent in France, and secondly by focusing on the application of this theory to mental health. Bringing to light medical treatises and theses from this period which have so far remained unexamined, it shows that examining the development and reception of medical theories form the past can help us today in understanding both the pitfalls and promise of research in this area.

Gastroenvironmental distress: metaphorical antecedents of the gut microbiome

The human gut has been viewed for centuries as a potential mediator of systemic disease. The theory of autointoxication, which found its clearest articulation in the late nineteenth and early twentieth centuries, focused on altered bowel habits as the cause of widespread physical decay and advocated for the pursuit of health through regular defecation. More recently, under the banner of the microbiome, research on commensal bacteria makes a similar case for associations between alimentary dynamics and illness manifestations far outside the gastrointestinal tract. Surface distinctions between these two conceptual frameworks are apparently antipodal, the former championing emptiness and sterility, the latter abundance and restoration. Within both models, however, persists a common anxiety about the detrimental effects of civilisation on the body in relation to the natural world. As scientific understanding of the microbiome continues to mature, acknowledging the historical and moral parameters of its borrowed ecological idiom may facilitate critical distinctions between what is true and what feels like it should be.

Constipation and risk of cardiovascular disease among postmenopausal women

BACKGROUND

Constipation is common in Western societies, accounting for 2.5 million physician visits/year in the US. Because many factors predisposing to constipation also are risk factors for cardiovascular disease, we hypothesized that constipation may be associated with increased risk of cardiovascular events.

METHODS

We conducted a secondary analysis in 93,676 women enrolled in the observational arm of the Women's Health Initiative. Constipation was evaluated at baseline by a self-administered questionnaire. Estimates of the risk of cardiovascular events (cumulative end point including mortality from coronary heart disease, myocardial infarction, angina, coronary revascularization, stroke, and transient ischemic attack) were derived from Cox proportional hazards models adjusted for demographics, risk factors, and other clinical variables (median follow-up 6.9 years).

RESULTS

The analysis included 73,047 women. Constipation was associated with increased age, African American and Hispanic descent, smoking, diabetes, high cholesterol, family history of myocardial infarction, hypertension, obesity, lower physical activity levels, lower fiber intake, and depression. Women with moderate and severe constipation experienced more cardiovascular events (14.2 and 19.1 events/1000 person-years, respectively) compared with women with no constipation (9.6/1000 person-years). After adjustment for demographics, risk factors, dietary factors, medications, frailty, and other psychological variables, constipation was no longer associated with an increased risk of cardiovascular events except for the severe constipation group, which had a 23% higher risk of cardiovascular events.

CONCLUSION

In postmenopausal women, constipation is a marker for cardiovascular risk factors and increased cardiovascular risk. Because constipation is easily assessed, it may be a helpful tool to identify women with increased cardiovascular risk.

Management of childhood constipation: parents’ experiences

BACKGROUND

Constipation in childhood is common and places a burden on child health services. Whilst constipation can have a variety of causes, for most children it is usually non-organic and requires limited intervention. It has been suggested that health professionals can resent consultations for such a common problem, believing them to be inappropriate. However, they can underestimate the impact of this condition, leading to adverse clinical effects, as well as parental dissatisfaction. Little research has explored parents' experiences of consulting health professionals about the management of childhood constipation.

AIM

To explore parents' experiences of consulting health professionals about management of childhood constipation and to use the findings to inform more effective therapeutic encounters when responding to parental concerns.

METHODS

A phenomenological approach was adopted, using in-depth interviews with parents of 14 children receiving health interventions for constipation.

FINDINGS

Six themes emerged from analysis including: 'enduring and extreme constipation', which reflected the substantial and sustained impact of the child's constipation; 'dismissed and fobbed off', which captured parents' feelings that their concerns were frequently dismissed by health professionals; 'asserting the need for action', a perception that they had reached a point at which they had to demand some intervention; and 'validation and acknowledgement', which reflected acknowledgment that, finally, their concerns for their child had been taken seriously and acted on.

DISCUSSION

The findings indicate a failure by some health professionals to appreciate fully the significance of childhood constipation, thereby appearing to be unconcerned and insensitive to the needs of child and family. The impact of this is a potential loss of trust in health professionals by parents, which can then have implications for how they perceive and access health services for management of this common childhood problem. The findings offer an insight into parental experiences and indicate the need for a more sensitive approach during health consultations.