From the Guidelines
D-lactic acidosis is a serious condition that requires prompt treatment with dietary modification and antibiotics to reduce morbidity and mortality. The pathophysiology of D-lactic acidosis involves the proliferation of anaerobic bacteria in stagnant loops of bowel, leading to the production of D-lactic acid, which can cause a high anion gap acidosis 1. This condition is often associated with small intestinal bacterial overgrowth (SIBO) and can occur in patients with disorders of intestinal motility, gastric acid secretion, or other mechanisms that prevent bacterial overgrowth. Some key features of the pathophysiology include:
- Bacterial overgrowth in the intestines, particularly of species that ferment carbohydrates to produce D-lactate
- Accumulation of D-lactate in the bloodstream due to the lack of sufficient D-lactate dehydrogenase in humans
- Metabolic acidosis with an increased anion gap
- Neurological symptoms such as confusion, slurred speech, ataxia, and even coma Two effective treatments for D-lactic acidosis include:
- Dietary modification: restricting carbohydrate intake, particularly simple sugars that are easily fermented by bacteria, while maintaining adequate nutrition through proteins and fats
- Antibiotic therapy: using metronidazole or vancomycin to reduce the bacterial load responsible for D-lactate production, as described in the management of adult patients with severe chronic small intestinal dysmotility 1.
From the Research
Pathophysiology of D-lactic acidosis
- D-lactic acidosis is a serious complication of short bowel syndrome (SBS) in children with intestinal failure (IF) 2
- Malabsorbed carbohydrates are metabolized by bacteria in the intestine to D-lactate, which can lead to metabolic acidosis and neurologic symptoms 2, 3
- Excessive production of D-lactate by abnormal bowel flora overwhelms normal metabolism of D-lactate and leads to an accumulation of this enantiomer in the blood 3
- The condition is characterized by unexplained metabolic acidosis, neurologic signs or symptoms, and high clinical suspicion of D-lactic acidosis 2
Treatments for D-lactic acidosis
- Sodium bicarbonate may be used to correct severe acidemia, but its use is controversial and may have untoward effects such as decreasing vasomotor tone and inducing intracellular acidosis 4, 5
- Other potential treatments include addressing the underlying cause of the condition, such as treating small bowel bacterial overgrowth or managing short bowel syndrome 2, 3
- In some cases, dialysis or other buffers such as THAM or Carbicarb may be considered as alternative treatments for lactic acidosis 5