You should always be suspicious of claims of this sort. Be doubly suspicious if the health claims focus on disorders such as leaky gut and fibromyalgia, which we really don't understand well and may be difficult to treat; be triply suspicious if the products are sold through multi-level marketing.
The current promotion of glyconutrients is a case in point: the products that ostensibly contain these natural plant sugars are represented as a newly discovered means to good health, but the scientific information presented in support of them is scant, and the quoted sources are not the peer-reviewed scientific journals to which we look for news of genuine medical breakthroughs. Another tip-off that these products are not what they may seem to be: statements that doctors don't know about them because (a) they are too busy to read or (b) they only pay attention to what the pharmaceutical companies are selling. While there may be some truth to these statements, if most doctors don't know about a "major health breakthrough," it can't be very major.
"Phytonutrients" are, simply, plant compounds we get from fruits and vegetables. If you include lots of fresh fruits and vegetables in your diet, you'll get an adequate supply of the nutrients these compounds contain, many of which are highly protective against heart disease and cancer. Whatever you may miss out on (if you don't always consume enough fruits and vegetables) can be supplied by taking a good multivitamin/mineral supplement. You don't have to buy expensive products to get the benefits of phyotonutrients.
Andrew Weil, M.D.