gastrointestinal microbiome

1 Emergency department visits and hospital admissions for acute
diverticulitis have increased
Emergency department visits for acute diverticulitis increased by 26.8% to
113.9 visits per 100 000 from 2006 to 2013 in the United States.1
Hospital admissions for diverticulitis increased 7.5% annually from 190 per 100 000 in 2008 to
310 per 100 000 in 2015 in Europe; the increase occurred predominantly among
patients aged younger than 60 years.2 Insufficient consumption of dietary fibre
is associated with this rise.
2 Symptoms of diverticulitis may be driven by inflammation rather
than infection
Contemporary evidence shows that use of antibiotics in uncomplicated cases of
diverticulitis neither accelerates recovery nor improves outcomes.2
A recent
study has suggested that chronic inflammation secondary to environmental risk
factors and alterations of the gut microbiome are now favoured causes over
microperforation or bacterial translocation.3
3 Most patients with uncomplicated diverticulitis can be treated as
outpatients with nonopiate analgesia rather than antibiotics
Cross-sectional imaging that shows inflamed colonic diverticula without perforation or abscess defines uncomplicated diverticulitis. Two randomized controlled trials that compared antibiotic and nonantibiotic treatment reported
no difference in recovery time, treatment duration or rate of recurrence.4,5
Updated guidelines recommend reserving antibiotics for patients taking
immunosuppressive medications and those with sepsis.1,2 Treating symptoms
with nonopiate analgesics avoids worsening bowel function and contributing
to opiate dependence.
4 Evidence of complicated diverticulitis should prompt emergent
surgical assessment and antibiotic treatment
Complicated diverticulitis, defined as radiologic evidence of perforation or intraabdominal abscess, has a 30-day mortality rate of 8.7%.2
Antibiotic therapy is indicated, and many patients require admission to hospital.1
Percutaneous drainage
of large abscesses (> 3 cm) or emergency surgery may be required.2
5 Colonoscopy and elective colon resection are not routinely required
after resolution of uncomplicated diverticulitis
Only 8.7% of patients with uncomplicated diverticulitis will present to hospital
with a second episode.1
Elective surgery should be determined by frequency
and severity of symptoms, rather than prevention of future complications.2
Risk of malignant disease after uncomplicated left-sided diverticulitis is similar to that of the general population (1%), and standard colon cancer screening guidelines should be followed.1
Complicated diverticulitis warrants an
interval colonoscopy, typically 6 weeks after resolution.1

The objective of this review is to provide an overview of intermittent fasting regimens, summarize the evidence on the health benefits of intermittent fasting, and discuss physiological mechanisms by which intermittent fasting might lead to improved health outcomes. A MEDLINE search was performed using PubMed and the terms "intermittent fasting," "fasting," "time-restricted feeding," and "food timing." Modified fasting regimens appear to promote weight loss and may improve metabolic health. Several lines of evidence also support the hypothesis that eating patterns that reduce or eliminate nighttime eating and prolong nightly fasting intervals may result in sustained improvements in human health. Intermittent fasting regimens are hypothesized to influence metabolic regulation via effects on (a) circadian biology, (b) the gut microbiome, and (c) modifiable lifestyle behaviors, such as sleep. If proven to be efficacious, these eating regimens offer promising nonpharmacological approaches to improving health at the population level, with multiple public health benefits.