I've yet to find any research that says any one thing causes bloat. I mean really, have you actually seen the list of "possible" causes of bloating??
Bloat in Dogs
Dog shows, mating, whelping, boarding, change in routine, new dog in household, etc.
Although purely anecdotal, we've heard of too many cases where a dog bloated after another dog (particularly a 3rd dog) was brought into the household; perhaps due to stress regarding pack order.
Activities that result in gulping air
Eating habits, especially...
Elevated food bowls
Eating dry foods that contain citric acid as a preservative (the risk is even worse if the owner moistens the food)
Eating dry foods that contain fat among the first four ingredients
Insufficient pancreatic enzymes, such as Trypsin (a pancreatic enzyme present in meat)
Dogs with untreated Exocrine Pancreatic Insufficiency (EPI) and/or Small Intestinal Bacterial Overgrowth (SIBO) generally produce more gas and thus are at greater risk New
Dilution of gastric juices necessary for complete digestion by drinking too much water before or after eating
Eating gas-producing foods (especially soybean products, brewer's yeast, and alfalfa)
Drinking too much water too quickly (can cause gulping of air)
Exercise before and especially after eating
Especially having a first-degree relative who has bloated
Dogs who have untreated Exocrine Pancreatic Insufficiency (EPI) are considered more prone to bloat New
Gas is associated with incomplete digestion
Build & Physical Characteristics
Having a deep and narrow chest compared to other dogs of the same breed
Fearful or anxious temperament
Prone to stress
History of aggression toward other dogs or people
The "prevention" or "risk reduction" precautions list is just as long and that's just one place. Other places have other opinions (Such as putting the bowl on the ground causes bloating or advice to soak the dogs food to prevent bloating) but nothing I've ever read has a single pin point on what causes it or what can actually prevent it for sure. I think the best thing is to do what YOU are comfortable with and pray for the best. (As well as keeping something like Gas-X on hand and knowing the symptoms!!)
Personally I raise the bowl for my large dogs. I currently have an 8" feeder which I originally bought for my boy, Chance. I got it for like $15 from Wal-Mart which included 2 metal bowls. I plan to get a higher feeder eventually since Gretchen is taller then Chance was and I feel like she'd be more comfortable with a taller one.
Just the Right Height Feeder, Black: Dogs : Walmart.com
< - That's similar to what I currently have only it's taller than what is pictured.
Neater Feeder Dog Bowl: Dogs : Walmart.com
< - I plan to go for something similar to that next since Gretchen is such a messy eater/drinker. Lol!
I also soak my dogs food when I'm not feeding raw, again, it's a personal choice.
I think the main thing people can really agree on is feeding at least 2 meals a day to break it down into smaller feedings (And even then some do once a day feeding - I feed twice a day mostly so I don't have my dogs digging in the trash after food from hunger) and don't exercise your dog right before or after feeding. The deep chested breed being prone to bloating thing is about the most proven truth to the whole thing.