While he does not say it explicitly, he found no prevalent infections nor any prevalent immune system problems in people with ME/CFS. Granted, he found some leads with regards to IL-17 and eotoxins – but I am cautious and don't expect that anything will come from this.
And while I think that there is possibly a connection to the gut (and to nutrition!) in many diseases, I however think the reason that Lipkin looks in the gut is because he has exhausted the paths of inquiry that involve the body "proper".
Furthermore Lipkin appears to think that ME/CFS is one "monolithic" disease, so the only place where this one disease must hide (in his view) is in the microbiome in the gut.
I think he is wrong on two accounts:
1. I think there is good evidence that ME/CFS is not one monolithic disease, but instead a set of symptoms that can be caused by several diseases.
2. Lipkin is – as so many in medical research and the medical profession – unaware of the pathogenic potential of some the foods we eat (with dairy, cereal grains and seed oils/PUFA/TFA in my mind being probably the prime suspects).
For me, this is the disenchantment of Lipkin, as I had some hope that he might be able find at least one prevalent disease in people with ME/CFS.
(And BTW some of the things he said on "Autism and GI complains", on "Kawasaki syndrome and candida in the troposphere" and on "Chronic Lyme" are borderline woo. I do not think that Lipkin is a good ally. However if he investigates these things properly, and then clearly announces if he draws a blank, then I am OK with his lines of inquiry. The problem starts when he does not clearly say when he draws a blank…)
Personally I don't expect that Lipkin/Horning will find anything useful in the gut/microbiome – but it is good that they continue their inquiry, if only that they might spread more awareness of the disease or might find something by a lucky coincidence. One never knows…
[Postscript] One other thing is noteworthy: Lipkin found no evidence whatsoever that ME/CFS is caused by HHV-6 / HHV-6B. He found 3 or 4 patients – out of 586(!) – with HHV-6 or HHV-6B. This more or less invalidates the entire argument by the HHV proponents that ME/CFS is caused by an ongoing HHV infection. I think especially the attention given to Montoya (and others) in that regards is not warranted.
[Postscript 2] One more thing: As Lipkin didn't explicitly say it, let me put it in clear words:
Lipkin found no evidence for an ongoing infection in people with ME/CFS.
Clear enough for you?
If ME/CFS is caused* by pathogens (viruses or possibly bacteria), then they are long gone after the initial acute infection**. A case of "hit and run", if you want – the pathogen is gone, the damage stays.
No need to treat a pathogen that is gone, as that will usually do more harm than good. Or as they say at NASA:
Things are never so bad that they can't be made worse.
So the first order of business: Don't make things worse. Anti-viral and anti-bacterial and anti-whatnot medications have a high potential to make things worse – best to use them only if you are really really sure.
So, if there is no pathogen, what can you do? The best one could do is to identify the damage, and try to treat it (e.g. orthostatic intolerance with medication targeting the blood preasure – speak with your doctor!). If there is anything that alleviates symptoms, then doing it might be a good ides. Change nutrition, try a Paleo Diet, try an Eleminaion Diet. But please, stop claiming that phantom ME/CFS viruses, and phantom ME/CFS bacteria, and phantom ME/CFS fungi supposedly hide in the gut of people with ME/CFS, or in their tissues, or god knows where – you are hurting yourself and hurting other people.
PLEASE. STOP. IT.
* There seems however to be evidence to indicate that acute infections can cause ME/CFS in some cases.
** Unless you are one of those rare 1 in a 100 ME/CFS cases were it is clearly established that there is an ongoing infection – and no, "Chronic Lyme" is not a ongoing infection, and neither is "Candida", nor "Chlamydophila pneumoniae" or any other somesuch woo terms being peddled by people who don't know better. These are makebelieve terms that only fool people (including those who doctors who use these terms).