Published online Apr 21, 2021. doi: 10.3748/wjg.v27.i15.1643
Peer-review started: December 22, 2020
First decision: January 27, 2021
Revised: February 4, 2021
Accepted: March 10, 2021
Article in press: March 10, 2021
Published online: April 21, 2021
In the early stage of acute pancreatitis (AP), a large number of cytokines induced by local pancreatic inflammation seriously destroy the intestinal barrier function, resulting in intestinal bacteria and endotoxins in the blood, causing inflammatory storms, and leading to multiple organ failure. Hydrogen breath testing is currently used for many diseases of the digestive system, such as lactose intolerance, irritable bowel syndrome, dyspepsia, and non-alcoholic fatty liver. This test, as an alternative method to detect small intestinal bacterial overgrowth (SIBO), was used to indirectly reflect the number of intestinal bacteria in AP. This study aimed to examine the change in intestinal bacteria measured using the hydrogen breath test in the early stage of AP to elucidate the relationship between intestinal bacteria and acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). Early clinical intervention and maintenance of intestinal barrier function will be very beneficial in controlling the development of severe AP (SAP).
Clinical trials showed that intestinal bacteria in AP patients were different to those in healthy people and the abundance of potential pathogenic bacteria such as Enterobacteriaceae and Enterococcus increased significantly while the abundance of beneficial bacteria such as Bifidobacterium decreased significantly. Animal experiments showed that not only the changes in intestinal bacteria in patients with AP were verified, but also there was a correlation between the changes in intestinal bacteria and organ failure. However, neither of them showed a relationship between intestinal bacteria and organ failure in the early stage of AP. If we can understand the change in intestinal bacteria using the hydrogen breath test in the early stage of AP, in order to understand the relationship between intestinal bacteria and ALI/ARDS, we can intervene and maintain the stability of intestinal barrier function as soon as possible, which will be very beneficial in controlling the development of SAP.
Maintaining intestinal barrier function and reducing and preventing intestinal bacteria translocation have become the key to controlling the occurrence and development of SAP. This reduces complications in the early stage of the disease. We performed the present study to investigate the changes in organ function and intestinal bacteria in AP, and to explore the correlation between SIBO and AP organ function.
Principle of the hydrogen breath test: after taking lactulose (nonabsorbable sugar), it reaches the cecum and is fermented with coliform bacteria to produce hydrogen and methane, which are absorbed into the systemic circulation and exhaled through the lung. When the hydrogen concentration in the exhaled breath exceeds the baseline, it is diagnosed as SIBO. In this study, a portable hydrogen expiratory detector was used to detect the patients’ expired hydrogen concentration to diagnose SIBO. The change in exhaled hydrogen concentration can reflect the number of bacteria in the small intestine.
The results showed that in 37 SAP patients with ARDS, the average hydrogen production rate at admission was 1.15 ± 0.58, at 72 h was 2.85 ± 4.79 and at 96 h was 1.31 ± 0.71. In 28 SAP patients without ARDS, the average hydrogen production rate at admission was 2.39 ± 2.61, at 72 h was 1.68 ± 1.85, and at 96 h was 1.84 ± 1.86. The increase in intestinal bacteria in patients with SAP within 72 h after admission was related to the occurrence of ARDS. How to effectively maintain the stability of intestinal barrier function in the early stage of the disease and prevent the overgrowth of intestinal bacteria is a problem to be solved.
In this study, intestinal bacterial overgrowth in the early stage of SAP was associated with ARDS. Moreover, the occurrence of ARDS was related to SIBO within 72 h of admission. It is of guiding significance to maintain the stability of intestinal barrier function in the early stage in order to reduce the complications of early organ failure and late infection.
How to effectively maintain the stability of intestinal barrier function and prevent the excessive growth of intestinal bacteria in the early stage of disease, in order to reduce the occurrence and development of SAP, is the future research direction.