I have written on the role of GABA in autism here and here and here. GABA is involved in calming neural activity, and having less of it is associated with autism. Now we have discovered a gut bacterium that seems to survive only on GABA.
Many of us on the spectrum also have gut problems. It may be that we need these bacteria, named KLE1738, but it also may be that one can have too many. Or, seemingly oddly, not enough.
It may very well be that one needs these bacteria to clear out GABA. Without enough KLE1738 to eat excess GABA, it’s likely that GABA would get converted back to glutamate (enzymes work both ways, after all). This would keep glutamate levels high, and glutamate both contributes to positive feedback in the brain and to leaky gut.
This may in fact be the more likely scenario simply because too many KLE1738 would result in starvation and result in the numbers dwindling back to normal. At the same time, one could imagine a scenario where there is a boom-bust cycle of KLE1738, with an alternation between too many and too few. Both too many and two few would result in GABA imbalances. And these swings could also result in the seeming bipolar behaviors we see in many on the spectrum.