Intestinal Bacterial Overgrowth After Roux-en-Y Gastric Bypass

Abstract

The aim of the present study was to report the occurrence of serious subnutrition, associated to intestinal bacterial overgrowth, in two patients submitted to bariatric surgery. Two female patients (body mass index, 49 and 50 kg/m(2), respectively) were submitted to Y-en-Roux gastric bypass. The first patient evolved a 52% loss of body weight within 21 months after surgery; the other, a 34% loss of initial body weight within 15 months after surgery, results corresponding, respectively, to 62 and 45 kg weight losses. However, both patients reported asthenia, hair fallout, and edema, and one also reported diarrhea, but none was feverish. Their respective albuminemias were of 24 and 23 g/l. A respiratory hydrogen test suggested bacterial hyperproliferation. Thirty days after ciprofloxacin and tetracyclin treatments, they showed improved albumin levels and nutritional states, both confirmed by results of hydrogen breath tests. Bacterial overgrowth is an important complication that can compromise clinical evolution of patients submitted to intestinal surgery like gastroplasty with Y-Roux anastomosis. In cases of clinical suspicion or a confirmed diagnosis, adequate antibiotics, sometimes requiring to be cyclically repeated, should be administered.

The Evolution of Stomach Acidity and Its Relevance to the Human Microbiome

“…A consequence of this procedure is an increase in gastric pH levels that range from 5.7 to 6.8. We would predict that the intestines of those individuals who have had gastric bypass surgery should be more likely to experience microbial overgrowth, a pattern that is supported by recent work [ 25 ]. We see similar patterns in other clinical cases such as oesophagitis in which treatment involves the use of proton-pump inhibitors and celiac disease where delayed gastric emptying is associated with reduced acidity [ 43 – 45 ].…”

Bariatric Surgery in Obesity: Effects on Gut Microbiota and Micronutrient Status

“…The inflammatory response following the luminal overgrowth of atypical microbes elicits changes of the epithelial cells that cause villous atrophy and/or stimulate the synthesis of inflammatory cytokines leading to an impaired absorptive capacity of macro-and micro-nutrients. Fat and fat-soluble vitamins' (particularly A, E, and D) malabsorption occurs because of improper micelle formation due to bacterial deconjugation of bile acids [84,88]. However, vitamin K levels are generally normal or elevated in patients with SIBO since bacteria are able to synthesize menaquinone [89].…”

“…Lakhani et al showed, in a retrospective analysis of 80 patients submitted to RYGB, that thiamine deficiency measured as whole-blood thiamine diphosphate level was lower than the reference range in 39 patients [91]. Of these patients, 28 presented elevated folate plasma levels, a marker suggesting the presence of SIBO [88], and 15 were also diagnosed with SIBO by undergoing glucose-hydrogen breath testing. Persistent thiamine deficiency rapidly resolved after initiation of antibiotic therapy to treat SIBO [91].…”

“…RYGB leads to the onset of secondary megaloblastic anemia. Machado et al showed, in a case report of two patients submitted to RYGB which tested positive for SIBO postoperatively, that although antibiotic treatment improved hemoglobin levels, mean cell volume was still increased while B12 level was below the normal range [88].…”

Medical Complications of Bariatric Surgery: Focus on Malabsorption and Dumping Syndrome

“…Second, increasing the jejunal part of the biliopancreatic limb by 30 cm would further delay delivery of digestive secretions to the alimentary stream and it would accentuate intraluminal destruction of pancreatic lipase [11]. Moreover, longer biliopancreatic limbs may be more apt to develop bacterial overgrowth, which would deconjugate bile acids and further retard digestion of dietary fat [12,13,14]. …”